A028386 - OEIS

The OEIS is supported by the many generous donors to the OEIS Foundation.

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Other ways to Give

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

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

LINKS

Table of n, a(n) for n=1..29.

P. 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

STATUS

approved