A111417 a(n) = A034869(n) - A008311(n).

0, 0, 1, 0, 0, 0, 3, 0, 0, 0, 0, 0, 10, 0, 0, 0, 0, 0, 0, 0, 35, 0, 0, 0, 0, 0, 0, 0, 0, 0, 126, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 462, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1716, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 6435, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 24310, 0

Offset

0,7

Links

Table of n, a(n) for n=0..91.

Formula

a(n) = A001700(m) if n = (m+1)*(m+2) and a(n) = 0 otherwise.

Crossrefs

Sequence in context: A356302 A308275 A308254 * A007271 A327449 A320179

Adjacent sequences: A111414 A111415 A111416 * A111418 A111419 A111420

Keyword

easy,nonn

Author

Philippe Deléham, Nov 13 2005

Status

approved