cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A343753 Number of partitions of prime(n) containing a prime number of primes.

Original entry on oeis.org

0, 0, 2, 6, 26, 49, 154, 258, 666, 2404, 3588, 11096, 22477, 31620, 61247, 157725, 387527, 518155, 1208470, 2086019, 2726745, 5975695, 9935799, 20882243, 54355088, 86547260, 108874661, 171286370, 214236058, 333331046, 1486031972, 2246585402, 4132451733
Offset: 1

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Author

Paolo Xausa, May 01 2021

Keywords

Examples

			a(4) = 6 because there are 6 partitions of prime(4) = 7 that contain a prime number of primes (including repetitions). These partitions are [5,2], [3,3,1], [3,2,2], [3,2,1,1], [2,2,2,1], [2,2,1,1,1].
		

Crossrefs

Programs

  • Mathematica
    nterms=20;Table[Total[Map[If[PrimeQ[Count[#, _?PrimeQ]],1,0] &,IntegerPartitions[Prime[n]]]],{n,1,nterms}]
  • PARI
    forprime(p=2, 67, my(m=0); forpart(X=p, my(j=0); for(k=1, #X, if(isprime(X[k]), j++));if(isprime(j),m++)); print1(m, ", ")) \\ Hugo Pfoertner, May 01 2021