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A055890 CIK transform of partition numbers A000041. 3
1, 1, 3, 6, 14, 28, 68, 148, 358, 845, 2061, 5018, 12458, 30922, 77557, 195154, 493809, 1253614, 3195210, 8166758, 20935826, 53799072, 138571332, 357647566, 924846881, 2395702829, 6215779536, 16150985916, 42024260088, 109485000778 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Table of n, a(n) for n=0..29.

C. G. Bower, Transforms (2)

P. Flajolet and M. Soria, The Cycle Construction. In SIAM J. Discr. Math., vol. 4 (1), 1991, pp. 58-60.

P. Flajolet and M. Soria, The Cycle Construction. [pdf file]

MATHEMATICA

nmax = 30;

f[x_] = 1/Product[1 - x^n, {n, 1, nmax}] - 1;

gf = 1+Sum[(EulerPhi[n]/n)*Log[1/(1 - f[x^n])] + O[x]^nmax, {n, 1, nmax}];

CoefficientList[gf, x] (* Jean-Fran├žois Alcover, Jul 29 2018, from PARI *)

PROG

(PARI)

N = 66;  x = 'x + O('x^N);

f(x) = 1 / prod(n=1, N, 1-x^n ) - 1;  \\ A055890

gf = 1 + sum(n=1, N, eulerphi(n)/n*log(1/(1-f(x^n)))  );

v = Vec(gf)

/* Joerg Arndt, Jan 21 2013 */

CROSSREFS

Cf. A055889, A000142.

Sequence in context: A224840 A132891 A200544 * A306884 A219768 A038359

Adjacent sequences:  A055887 A055888 A055889 * A055891 A055892 A055893

KEYWORD

nonn

AUTHOR

Christian G. Bower, Jun 09 2000

STATUS

approved

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Last modified March 18 17:51 EDT 2019. Contains 321292 sequences. (Running on oeis4.)