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A100427 Bisection of A000081 (odd part). 3
1, 2, 9, 48, 286, 1842, 12486, 87811, 634847, 4688676, 35221832, 268282855, 2067174645, 16083734329, 126186554308, 997171512998, 7929819784355, 63411730258053, 509588049810620, 4113254119923150, 33333125878283632, 271097737169671824, 2212039245722726118 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Alois P. Heinz, Table of n, a(n) for n = 0..400

MAPLE

with(numtheory):

b:= proc(n) option remember; local d, j; `if`(n<2, n,

      (add(add(d*b(d), d=divisors(j))*b(n-j), j=1..n-1))/(n-1))

    end:

a:= n-> b(2*n+1):

seq(a(n), n=0..50);  # Alois P. Heinz, May 16 2013

MATHEMATICA

b[n_] := b[n] = If[n <= 1, n, Sum[Sum[d*b[d], {d, Divisors[j]}]*b[n-j], {j, 1, n-1}]/(n-1)]; a[n_] := b[2*n+1]; Table[a[n], {n, 0, 30}] (* Jean-Fran├žois Alcover, Mar 19 2014, after Alois P. Heinz *)

CROSSREFS

Cf. A000081, A100034, A299113.

Sequence in context: A153390 A118341 A171803 * A214404 A074143 A198892

Adjacent sequences:  A100424 A100425 A100426 * A100428 A100429 A100430

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane, Nov 20 2004

EXTENSIONS

More terms from Joshua Zucker, May 12 2006

STATUS

approved

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Last modified December 12 17:59 EST 2019. Contains 329960 sequences. (Running on oeis4.)