A096569 - OEIS

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A096569

Number of compositions of n with first part 1 and no equal adjacent parts; this is column 1 of the array in A096568.

1, 0, 1, 2, 2, 5, 9, 14, 25, 46, 78, 136, 242, 419, 733, 1291, 2251, 3938, 6905, 12073, 21129, 37001, 64741, 113304, 198344, 347126, 607532, 1063387, 1861149, 3257410, 5701362, 9978711, 17465052, 30568232, 53501720, 93640745, 163894183

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OFFSET

1,4

LINKS

Table of n, a(n) for n=1..37.

FORMULA

Define s(0)=1, T(1, 1)=1 and T(i, j)=0 for j>i. For n>=2 and 1<=k<=n, define s(n)=T(n, 1)+T(n, 2)+...+T(n, n) and T(n, k)=s(n-k)-T(n-k, k). (This is array A096568.)

CROSSREFS

Cf. A003242, A096568, A096570, A096571, A096572.

Sequence in context: A262614 A184296 A131133 * A076607 A325104 A054229

Adjacent sequences: A096566 A096567 A096568 * A096570 A096571 A096572

KEYWORD

nonn

AUTHOR

Clark Kimberling, Jun 27 2004

STATUS

approved