A274579 - cp's OEIS frontend

A274579 Values of k such that 2k+1 and 5k+1 are both triangular numbers.

n	a(n)
1	0
2	1
3	7
4	27
5	540
6	2002
7	10660
8	39501
9	779247
10	2887450
11	15372280
12	56960982
13	1123674201
14	4163701465
15	22166817667
16	82137697110
17	1620337419162
18	6004054625647
19	31964535704101
20	118442502272205
21	2336525434757970
22	8657842606482076
23	46092838318496542

[0, 1, 7, 27, 540, 2002, 10660, 39501, 779247, 2887450, 15372280, 56960982, 1123674201, 4163701465, 22166817667, 82137697110, 1620337419162, 6004054625647, 31964535704101, 118442502272205, 2336525434757970, 8657842606482076, 46092838318496542]

cp's OEIS Frontend

A274579 Values of k such that 2k+1 and 5k+1 are both triangular numbers.

Table of values

List of values

cp's OEIS Frontend

A274579 Values of k such that 2*k+1 and 5*k+1 are both triangular numbers.

Table of values

List of values

A274579 Values of k such that 2k+1 and 5k+1 are both triangular numbers.