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A171634 Number of compositions of n such that the number of parts is divisible by the greatest part. 2
1, 1, 3, 2, 8, 13, 21, 38, 89, 173, 302, 545, 1109, 2309, 4564, 8601, 16188, 31365, 62518, 125813, 251119, 493123, 956437, 1854281, 3633938, 7218166, 14444539, 28868203, 57300450, 112921744, 221760513, 436117749, 861764899, 1711773936 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Alois P. Heinz, Table of n, a(n) for n = 1..250

FORMULA

G.f.: Sum_{n>=0} Sum_{d|n} ((x^(d+1)-x)^n-(x^d-x)^n)/(x-1)^n.

MAPLE

b:= proc(n, t, g) option remember; `if` (n=0, `if` (irem(t, g)=0, 1, 0), add (b(n-i, t+1, max(i, g)), i=1..n)) end: a:= n-> b(n, 0, 0): seq (a(n), n=1..40); # Alois P. Heinz, Dec 15 2009

CROSSREFS

Cf. A168659, A171632.

Sequence in context: A088551 A301903 A165660 * A107300 A285787 A047946

Adjacent sequences:  A171631 A171632 A171633 * A171635 A171636 A171637

KEYWORD

easy,nonn

AUTHOR

Vladeta Jovovic, Dec 13 2009

EXTENSIONS

More terms from Alois P. Heinz, Dec 15 2009

STATUS

approved

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Last modified February 16 15:17 EST 2020. Contains 331961 sequences. (Running on oeis4.)