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.

A058698 a(n) = p(P(n)), P = primes (A000040), p = partition numbers (A000041).

Original entry on oeis.org

2, 3, 7, 15, 56, 101, 297, 490, 1255, 4565, 6842, 21637, 44583, 63261, 124754, 329931, 831820, 1121505, 2679689, 4697205, 6185689, 13848650, 23338469, 49995925, 133230930, 214481126, 271248950, 431149389, 541946240, 851376628, 3913864295, 5964539504, 11097645016
Offset: 1

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Author

N. J. A. Sloane, Dec 31 2000

Keywords

Comments

Number of partitions of n-th prime. - Omar E. Pol, Aug 05 2011

Examples

			a(2) = 3 because the second prime is 3 and there are three partitions of 3: {1, 1, 1}, {1, 2}, {3}.
		

Crossrefs

Programs

  • Haskell
    import Data.MemoCombinators (memo2, integral)
    a058698 n = a058698_list !! (n-1)
    a058698_list = map (pMemo 1) a000040_list where
       pMemo = memo2 integral integral p
       p _ 0 = 1
       p k m | m < k     = 0
             | otherwise = pMemo k (m - k) + pMemo (k + 1) m
    -- Reinhard Zumkeller, Aug 09 2015
  • Mathematica
    Table[PartitionsP[Prime[n]], {n, 30}] (* Vladimir Joseph Stephan Orlovsky, Dec 05 2008 *)

Formula

a(n) = A000041(A000040(n)). - Omar E. Pol, Aug 05 2011