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A327550 Number of compositions of partitions of 2n with exactly n compositions. 2
1, 2, 8, 24, 80, 224, 704, 1920, 5632, 15360, 43008, 114688, 315392, 827392, 2211840, 5767168, 15138816, 38928384, 100925440, 256901120, 657457152, 1660944384, 4202692608, 10527703040, 26424115200, 65699577856, 163477192704, 403995361280, 998043025408 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Alois P. Heinz, Table of n, a(n) for n = 0..900

FORMULA

a(n) = A327549(2n,n).

a(n) ~ 2^n * exp(Pi*sqrt(2*n/3)) / (4*sqrt(3)*n). - Vaclav Kotesovec, Sep 19 2019

MAPLE

b:= proc(n, i, k) option remember; `if`(n=0, 1, `if`(i<1 or

      k<1, 0, b(n, i-1, k)+ 2^(i-1)*b(n-i, min(n-i, i), k-1)))

    end:

a:= n-> b(2*n$2, n)-`if`(n=0, 0, b(2*n$2, n-1)):

seq(a(n), n=0..40);

CROSSREFS

Cf. A327549.

Sequence in context: A093833 A228404 A006952 * A034741 A063727 A085449

Adjacent sequences:  A327547 A327548 A327549 * A327551 A327552 A327553

KEYWORD

nonn

AUTHOR

Alois P. Heinz, Sep 16 2019

STATUS

approved

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Last modified December 5 22:37 EST 2019. Contains 329782 sequences. (Running on oeis4.)