A024727 - OEIS

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A024727

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)=4.

1

1, 1, 4, 4, 4, 4, 20, 36, 52, 132, 292, 580, 1252, 2628, 6196, 13412, 28884, 64516, 147140, 327684, 722116, 1615236, 3758292, 8500772, 19027572, 43203204, 100782308, 230210884, 522001572, 1193084612, 2800307188, 6441467748, 14722404372

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OFFSET

1,3

LINKS

Table of n, a(n) for n=1..33.

CROSSREFS

Sequence in context: A062732 A100777 A309501 * A024552 A264768 A201981

Adjacent sequences: A024724 A024725 A024726 * A024728 A024729 A024730

KEYWORD

nonn

AUTHOR

Clark Kimberling

STATUS

approved