A137155 a(n) = Sum_{k=0..[n/2]} C(2^k + n-2k-1, n-2k); equals the antidiagonal sums of triangle A137153.

1, 1, 2, 3, 5, 9, 17, 35, 80, 201, 561, 1771, 6298, 25217, 115440, 605243, 3609754, 24742305, 196470603, 1792166979, 18817616610, 230233601737, 3268914688382, 53509699527491, 1020486454701731, 22777217813040393, 589097686208575727

Offset

0,3

Links

Table of n, a(n) for n=0..26.

Prog

(PARI) a(n)=sum(k=0, n\2, binomial(2^k+n-2*k-1, n-2*k))

Crossrefs

Cf. A137153, A137154.

Sequence in context: A179807 A110113 A341960 * A014227 A334816 A064769

Adjacent sequences: A137152 A137153 A137154 * A137156 A137157 A137158

Keyword

nonn

Author

Paul D. Hanna, Jan 24 2008

Status

approved