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A007182 Dimension of n-th compound of a certain space.
(Formerly M1381)
2
1, 2, 5, 10, 23, 45, 94, 179, 358, 672, 1292, 2382, 4470, 8132, 14937, 26832, 48507, 86205, 153717, 270507, 476896, 832001, 1452283, 2513705, 4350072, 7475915, 12838338, 21919846, 37385434, 63450376, 107547996, 181525120, 305951060, 513772849, 861463730 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

REFERENCES

Y. Chiricota, Équations différentielles combinatoires et calcul symbolique in "FPSAC5": Formal Power Series and Algebraic Combinatorics, Fifth Conference, Florence, Jun 21-25 1993, Vol. 2, p. 123.

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

LINKS

Alois P. Heinz, Table of n, a(n) for n = 0..1000

MAPLE

b:= proc(n) option remember; `if`(n=0, 1, add(add(

      `if`(d<2, d, `if`(d::odd, 0, b(d/2)))*d,

       d=numtheory[divisors](j))*b(n-j), j=1..n)/n)

    end:

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

seq(a(n), n=0..40);  # Alois P. Heinz, Jul 08 2015

MATHEMATICA

b[n_] := b[n] = If[n==0, 1, Sum[Sum[If[d<2, d, If[OddQ[d], 0, b[d/2]]]*d, {d, Divisors[j]}]*b[n-j], {j, 1, n}]/n]; a[n_] := b[2*n]; Table[a[n], {n, 0, 40}] (* Jean-François Alcover, Feb 24 2016, after Alois P. Heinz *)

CROSSREFS

Sequence in context: A284139 A068054 A174542 * A191386 A323988 A026677

Adjacent sequences:  A007179 A007180 A007181 * A007183 A007184 A007185

KEYWORD

nonn

AUTHOR

Simon Plouffe

EXTENSIONS

a(0), a(17)-a(34) from Alois P. Heinz, Jul 08 2015

STATUS

approved

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Last modified June 17 19:57 EDT 2021. Contains 345085 sequences. (Running on oeis4.)