A028386 Numbers k such that k*(3k-1)/2 is a pentagonal palindrome.

1, 2, 4, 26, 44, 101, 693, 2173, 2229, 4228, 6010, 26466, 26906, 31926, 44059, 1258723, 1965117, 1979130, 2684561, 13280839, 59401650, 84885761, 100058581, 225563533, 316882086, 700457153, 818049201, 851649306, 1345679688, 2049123156, 6693818696, 18306458265, 18517422797

Offset

1,2

Links

Bert Dobbelaere, Table of n, a(n) for n = 1..57

Patrick De Geest, Palindromic Pentagonals

Crossrefs

Cf. A002069, A000326.

Sequence in context: A218258 A186431 A129894 * A362001 A259374 A155120

Adjacent sequences: A028383 A028384 A028385 * A028387 A028388 A028389

Keyword

nonn,base

Author

Patrick De Geest

Extensions

More terms from Patrick De Geest, Nov 15 1998

More terms from Bert Dobbelaere, Apr 15 2025

Status

approved