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A305198 Number of set partitions of [2n+1] with symmetric block size list of length A109613(n). 3
1, 1, 7, 56, 470, 10299, 91925, 3939653, 36298007, 2571177913, 24158837489, 2557117944391, 24350208829581, 3601150175699409, 34626777577615921, 6820331445080882282, 66066554102006208712, 16719951521837764142510, 162903256982698962545956 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Alois P. Heinz, Table of n, a(n) for n = 0..200

FORMULA

a(n) = A275281(2n+1,A109613(n)).

MAPLE

b:= proc(n, s) option remember; expand(`if`(n>s,

      binomial(n-1, n-s-1)*x, 1)+add(binomial(n-1, j-1)*

      b(n-j, s+j)*binomial(s+j-1, j-1), j=1..(n-s)/2)*x^2)

    end:

a:= n-> coeff(b(2*n+1, 0), x, n+irem(n+1, 2)):

seq(a(n), n=0..20);

CROSSREFS

Bisection (odd part) of A305197.

Cf. A109613, A275281, A275283.

Sequence in context: A155197 A147839 A126694 * A264912 A323216 A024091

Adjacent sequences:  A305195 A305196 A305197 * A305199 A305200 A305201

KEYWORD

nonn

AUTHOR

Alois P. Heinz, May 27 2018

STATUS

approved

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Last modified August 3 07:48 EDT 2020. Contains 336197 sequences. (Running on oeis4.)