This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A055923 Number of partitions of n in which each part occurs a prime number (or 0) times. 3

%I

%S 1,0,1,1,1,1,3,2,3,4,4,6,8,8,10,13,13,20,20,24,26,38,35,51,51,65,67,

%T 92,86,121,117,153,155,209,197,270,262,339,341,444,425,565,555,703,

%U 711,903,884,1135,1128,1397,1430,1766,1757,2193,2214,2691,2762,3344

%N Number of partitions of n in which each part occurs a prime number (or 0) times.

%H Alois P. Heinz, <a href="/A055923/b055923.txt">Table of n, a(n) for n = 0..1000</a>

%F EULER transform of b where b has g.f. Sum {k>0} c(k)*x^k/(1-x^k) where c is inverse EULER transform of characteristic function of prime numbers.

%F G.f.: Product(1+Sum(x^(i*prime(k)), k=1..infinity), i=1..infinity). - _Vladeta Jovovic_, Jan 08 2005

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

%p add(`if`(isprime(j), b(n-i*j, i-1), 0), j=1..n/i) +b(n, i-1)))

%p end:

%p a:= n-> b(n\$2):

%p seq(a(n), n=0..60); # _Alois P. Heinz_, May 31 2014

%t b[n_, i_] := b[n, i] = If[n == 0, 1, If[i<1, 0, Sum[If[PrimeQ[j], b[n-i*j, i-1], 0], {j, 1, n/i}] + b[n, i-1]]]; a[n_] := b[n, n]; Table[a[n], {n, 0, 60}] (* _Jean-François Alcover_, Nov 11 2015, after _Alois P. Heinz_ *)

%Y Cf. A000041, A007690, A055922.

%K nonn

%O 0,7

%A _Christian G. Bower_, Jun 23 2000

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified February 23 18:37 EST 2019. Contains 320438 sequences. (Running on oeis4.)