A024958 a(n) = Sum_{i=1..floor((n+2)/4)} a(2i-1)*a(n-2i+1), with a(1)=3 and a(2)=a(3)=1.

3, 1, 1, 3, 9, 28, 87, 270, 838, 2682, 8568, 27325, 87087, 284940, 929773, 3026424, 9843471, 32691629, 108290562, 357839667, 1181136576, 3967571310, 13290977466, 44410377199, 148240940865, 501864577470, 1694984858142, 5711630686332

Offset

1,1

Links

Table of n, a(n) for n=1..28.

Crossrefs

Sequence in context: A260883 A088749 A024737 * A014516 A247306 A016563

Adjacent sequences: A024955 A024956 A024957 * A024959 A024960 A024961

Keyword

nonn

Author

Clark Kimberling

Extensions

Offset corrected and title improved by Sean A. Irvine, Jul 30 2019

Status

approved