A120581 Hankel transform of sum{k=0..n, C(2k,k)*2^k}.

1, 4, -64, -28672, -17825792, -24696061952, -4398046511104, 6413125869375586304, 1279761316857673852911616, 565738597953418785628899770368, 372547299599873882347063111621541888, -5264848781000759906705331926184317767647232

Offset: 0

Author

Paul Barry, Jun 15 2006

Keywords

• easy
• sign

Crossrefs

Cf. A120580.

Formula

a(n)=4^(n+C(n,2))(-1)^n*sum{k=0..n, C(n+k,2k)(-2)^(n-k)}; a(n)=8^n*4^C(n,2)*sum{k=0..n, C(n+k,2k)(-2)^(-k)}; a(n)=4^n*4^C(n,2)(-1)^n*A087168(n);