```Scholars Journal of Engineering and Technology (SJET)
Sch. J. Eng. Tech., 2014; 2(3C):447-450
ISSN 2321-435X (Online)
ISSN 2347-9523 (Print)
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Research Article
Relations Among Polygonal Numbers Through The Integer Solutions Of
z2=6x2+y2
K.Meena1, S.vidhyalakshmi2, M.A.Gopalan3, R. Bhavani*4
Former VC, Bharathidasan University, Trichy-620024, Tamilnadu, India.
2,3
Professor, Department of Mathematics, Shrimati Indira Gandhi College, Trichy-620002, Tamilnadu, India
4
M.Phil student, Department of Mathematics, Shrimati Indira Gandhi College, Trichy-620002, Tamilnadu, India.
1
*Corresponding author
R. Bhavani
Email:
Abstract: The ternary quadratic equation given by Z  6 X  Y is considered. Employing its
solutions, relations among few special polygonal numbers are determined.
Keywords: Pell equations, Ternary quadratic equation.
2
2
2
non-zero integral
INTRODUCTION:
In [1-3], different patterns of m-gonal numbers are presented. In [4] explicit formulas for the rank of Triangular
numbers which are simultaneously equal to Pentagonal, Decagonal and Dodecagonal numbers in turn are presented. In
[5,6] the relations among the pairs of special m-gonal numbers generated through the solutions of the binary quadratic
equations are determined.
In this communication, we consider the ternary quadratic equation given by Z
relations among the pairs of special m-gonal numbers generated through its solutions.
2
 6 X 2  Y 2 and obtain the
2010 Mathematics subject classification: 11D09
NOTATIONS:
Tm .n : Polygonal number of rank n with m sides
METHOD OF ANALYSIS:
Consider the Diophantine equation
Z 2  6X 2  Y 2
(1)
whose general solutions are
X  6rs
Y  6r 2  s 2
Z  6r  s
2
(2)
2
where r and s are non-zero positive integers.
CHOICE (1):
The choices
2 M  1  6r 2  s 2 , 4 N  1  6r 2  s 2
(3)
in (1) leads to the relation that
"4T3, M  4T6, N  3 2 "
From (3), the values of ranks of the Triangular numbers and Hexagonal numbers are respectively given by
447
Bhavani R et al., Sch. J. Eng. Tech., 2014; 2(3C):447-450
6r 2  s 2  1
6r 2  s 2  1
M
, N 
4
2
For integer values of M and N, choose r  2k , s  2k  1
TABLE: 1- Examples
k
M
N
4(T3, M  T6, N )
1
12
3(4 2 )
2
52
120
6
22
3( 24 2 )
48
3(60 2 )
216
84
3(112 2 )
3
4
CHOICE (2):
The choices
2 M  1  6r 2  s 2 , 6 N  1  6r 2  s 2
(4)
in (1) leads to the relation that
"4T3, M  12T5, N  3 2 "
From (4), the values of ranks of the Triangular numbers and Pentagonal numbers are respectively given by
M
6r 2  s 2  1
6r 2  s 2  1
, N 
6
2
CASE: 1
choose r  4k  3, s  6k  5 . The corresponding integer values of M, N are
M  66k 2  102k  39, N  10k 2  14k  5
TABLE: 2- Examples
k
M
N
4T3, M  12T5, N
1
3
1
3( 2 2 )
2
99
327
17
3(70 2 )
53
3( 234 2 )
687
109
3(494 2 )
3
4
CASE: 2
choose r  4k  1, s  6k  1 . The corresponding integer values of M, N are
M  66k 2  30k  3, N  10k 2  6k  1
TABLE: 3- Examples
k
M
N
4T3, M  12T5, N
1
39
5
3( 30 2 )
2
207
507
29
3(154 2 )
73
3( 374 2 )
939
137
3(690 2 )
3
4
CHOICE (3):
The choices
2 M  1  6r 2  s 2 , 3 N  1  6r 2  s 2
(5)
in (1) leads to the relation that
448
Bhavani R et al., Sch. J. Eng. Tech., 2014; 2(3C):447-450
“ 8T
3, M
 3T
 6 2 "
8, N
From (5), the values of ranks of the Triangular numbers and Octagonal numbers are respectively given by
6r 2  s 2  1
6r 2  s 2  1
M
, N 
2
3
CASE: 1
choose r  6k  2, s  6k  1 .The corresponding integer values of M, N are
M  126k 2  78k  12 N  60k 2  44k  8
TABLE: 4-Examples
k
M
N
8T3, M  3T8, N
1
60
24
6(40 2 )
2
360
912
160
6( 220 2 )
792
6(544 2 )
1716
416
6(1012 2 )
3
4
CASE: 2
choose r  6k , s  6k  1 . The corresponding integer values of M, N are
M  126k 2  6k , N  60k 2  4k
TABLE: 5
k
M
N
8T3, M  3T8, N
1
132
56
6(84 2 )
2
516
1152
232
6( 312 2 )
528
6(684 2 )
2040
944
6(1200 2 )
3
4
CHOICE (4):
The choices
6 M  1  6r 2  s 2 , 2 N  1  6r 2  s 2
(6)
in (1) leads to the relation that
"8T3, M  24T5, N  6 2 "
From (6), the values of ranks of the Triangular numbers and Pentagonal numbers are respectively given by
M
6r 2  s 2  1
6r 2  s 2  1
N

,
2
6
CASE: 1
choose r  6k  2, s  6k  1 . The corresponding integer values of M, N are
M  126k 2  78k  12, N  30k 2  22k  4
TABLE: 6- Examples
k
M
N
8T3, M  24T5, N
1
60
12
6(40 2 )
2
360
912
80
6( 220 2 )
208
6(544 2 )
1716
396
6(1012 2 )
3
4
449
Bhavani R et al., Sch. J. Eng. Tech., 2014; 2(3C):447-450
CASE: 2
choose r  6k , s  6k  1 . The corresponding integer values of M, N are
M  126k 2  6k , N  60k 2  4k
TABLE: 7- Examples
k
M
N
8T3, M  24T8, N
1
132
28
6(84 2 )
2
516
1152
116
6( 312 2 )
264
472
6(684 2 )
3
4
2040
6(1200 2 )
CHOICE (5):
The choices
5 M  2  6r 2  s 2 , N  6r 2  s 2
(7)
in (1) leads to the relation that
"5T12, M  T4, N  6 2  4"
From (7), the values of ranks of the Dodecagonal numbers and Square numbers are respectively given by
6r 2  s 2  2
2
2
, N  6r  s
5
For integer values of M and N, choose r  5k  3, s  5k  3
M
TABLE: 8- Examples
k
M
N
5T12, M  T4, N  4
1
6
20
6(8 2 )
2
69
202
245
6(98 2 )
720
6( 288 2 )
405
1445
6(578 2 )
3
4
CONCLUSION:
To conclude, we may search for other relations to (1) by using special polygonal numbers.
ACKOWLEDGEMENT
* The financial support from the UGC, New Delhi (F-MRP-5123/14(SERO/UGC) March 2014) for a part of this paper is
gratefully acknowledged.
REFERENCES:
1. Dickson LE; History of theory of numbers, Chelisa publishing company, New York, Vol.2, 1971.
2. Kapur JN; Ramanujan’s Miracles, Mathematical sciences Trust society, 1997
3. Shailesh Shirali, Mathematical Marvels, A primer on Number sequences, University press, 2001.
4. Gopalan MA, Devibala S; Equality of Triangular numbers with special m-gonal numbers, Bulletin of the