A322610 - OEIS

A322610

Numbers that are sums (of a nonempty sequence) of consecutive centered triangular numbers.

1, 4, 5, 10, 14, 15, 19, 29, 31, 33, 34, 46, 50, 60, 64, 65, 77, 85, 96, 106, 109, 110, 111, 136, 141, 149, 160, 166, 170, 174, 175, 194, 195, 199, 226, 235, 245, 255, 258, 259, 260, 274, 302, 304, 316, 330, 335, 354, 361, 364, 365, 368, 369, 394, 409, 411, 434, 440, 460, 471, 490, 496, 500

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

OFFSET

1,2

LINKS

Table of n, a(n) for n=1..63.

Eric Weisstein's World of Mathematics, Centered Triangular Number

MATHEMATICA

anmax = 1000; nmax = Floor[Sqrt[2*anmax/3]] + 1; Select[Union[Flatten[Table[Sum[(3*k^2 + 3*k + 2)/2, {k, i, j}], {i, 0, nmax}, {j, i, nmax}]]], # <= anmax &] (* Vaclav Kotesovec, Dec 21 2018 *)

CROSSREFS

Cf. A005448, A005918 (2 consec), A006003, A034706, A320728, A322468, A322611, A322638, A322640.

Sequence in context: A236283 A357865 A366864 * A322468 A116930 A073119

Adjacent sequences: A322607 A322608 A322609 * A322611 A322612 A322613

KEYWORD

nonn

AUTHOR

Ilya Gutkovskiy, Dec 20 2018

STATUS

approved