A171006 Binomial(n-k-1,k) * binomial(n-k,k+1) where k = ceiling(n/4).

0, 0, 0, 1, 6, 1, 12, 60, 200, 150, 700, 2450, 7056, 8820, 31752, 97020, 261360, 426888, 1359072, 3864861, 10020010, 19324305, 57257200, 155739584, 393853824, 851005584, 2405321568, 6347376360, 15774544800, 37026362100, 101219995800, 261312846300

Offset

0,5

Links

Table of n, a(n) for n=0..31.

Crossrefs

Another lower bound for A094837. Cf. A171001, A171002, A171003.

Sequence in context: A163945 A013613 A122508 * A176121 A373845 A062190

Adjacent sequences: A171003 A171004 A171005 * A171007 A171008 A171009

Keyword

nonn

Author

John P. Linderman, Sep 02 2010

Status

approved