A024725 a(n) = Sum_{i=1..floor((n+1)/4)} a(2*i-1) * a(n-2*i+1), with a(1)=a(2)=1 and a(3)=3.

1, 1, 3, 3, 3, 3, 12, 21, 30, 66, 138, 264, 525, 1029, 2271, 4620, 9291, 19335, 41430, 86556, 178689, 373854, 814269, 1726698, 3620550, 7688712, 16786875, 35952933, 76375821, 163325109, 358773663, 773646114, 1656489261, 3572265090, 7856043150, 17039803998

Offset

1,3

Links

Table of n, a(n) for n=1..36.

Crossrefs

Sequence in context: A342400 A349924 A170858 * A269562 A214730 A153491

Adjacent sequences: A024722 A024723 A024724 * A024726 A024727 A024728

Keyword

nonn

Author

Clark Kimberling

Extensions

a(28) corrected by Sean A. Irvine, Jul 20 2019

Status

approved