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A066882 Number of partitions of n into prime divisors of n. 11
1, 0, 1, 1, 1, 1, 2, 1, 1, 1, 2, 1, 3, 1, 2, 2, 1, 1, 4, 1, 3, 2, 2, 1, 5, 1, 2, 1, 3, 1, 21, 1, 1, 2, 2, 2, 7, 1, 2, 2, 5, 1, 28, 1, 3, 4, 2, 1, 9, 1, 6, 2, 3, 1, 10, 2, 5, 2, 2, 1, 71, 1, 2, 4, 1, 2, 42, 1, 3, 2, 43, 1, 13, 1, 2, 6, 3, 2, 49, 1, 9, 1, 2, 1, 97, 2, 2, 2, 5, 1, 151, 2, 3, 2, 2, 2, 17, 1, 8 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,7

LINKS

Alois P. Heinz, Table of n, a(n) for n = 0..10000

FORMULA

Coefficient of x^n in expansion of 1/Product_{d is prime divisor of n} (1-x^d). - Vladeta Jovovic, Apr 11 2004

MAPLE

with(numtheory):

a:= proc(n) local b, l; l:= sort([factorset(n)[]]):

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

             b(m, i-1)+`if`(l[i]>m, 0, b(m-l[i], i))))

          end; forget(b):

      b(n, nops(l))

    end:

seq(a(n), n=0..100); # Alois P. Heinz, Feb 05 2014

MATHEMATICA

a[0] = 1; a[n_] := SeriesCoefficient[1/Product[1-x^d, {d, FactorInteger[n][[All, 1]]}], {x, 0, n}]; Table[a[n], {n, 0, 100}] (* Jean-Fran├žois Alcover, Jul 30 2015, after Vladeta Jovovic *)

CROSSREFS

Cf. A018818, A014652.

Sequence in context: A324837 A285572 A179926 * A300831 A068347 A284556

Adjacent sequences:  A066879 A066880 A066881 * A066883 A066884 A066885

KEYWORD

easy,nonn,look

AUTHOR

Naohiro Nomoto, Jan 26 2002

EXTENSIONS

More terms from Sascha Kurz, Mar 23 2002

Corrected by Vladeta Jovovic, Apr 11 2004

STATUS

approved

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Last modified August 4 09:03 EDT 2020. Contains 336201 sequences. (Running on oeis4.)