A024737 a(n) = Sum_{i=1..floor((n+1)/4)} a(2*i-1) * a(n-2*i+1), with a(1)=3 and a(2)=a(3)=1.

3, 1, 1, 3, 9, 27, 84, 261, 810, 2514, 8046, 25704, 81975, 261261, 854037, 2784540, 9057393, 29439855, 97650930, 323099676, 1066565907, 3517004046, 11791407663, 39431809098, 131550859650, 438453827928, 1481254263945, 4993010577093

Offset

1,1

Links

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

Crossrefs

Sequence in context: A112508 A260883 A088749 * A024958 A014516 A247306

Adjacent sequences: A024734 A024735 A024736 * A024738 A024739 A024740

Keyword

nonn

Author

Clark Kimberling

Status

approved