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.

Showing 1-3 of 3 results.

A167392 Characteristic function of partition numbers.

Original entry on oeis.org

0, 1, 1, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0
Offset: 0

Views

Author

Reinhard Zumkeller, Nov 03 2009

Keywords

Crossrefs

Cf. A167393.
For n >= 1, column 1 of A186114, also right border of A193870. - Omar E. Pol, Aug 14 2011

Programs

  • Haskell
    import Data.List.Ordered (member)
    a167392 = fromEnum . flip member a000041_list
    -- Reinhard Zumkeller, Nov 03 2015
  • Mathematica
    nmax = 14;
    (* nmax=14 gives P(nmax)+1 = 136 terms; nmax=33 gives 10144 terms *)
    PP = Table[PartitionsP[n], {n, 0, nmax}];
    a[n_] := Boole[MemberQ[PP, n]];
    Table[a[n], {n, 0, PartitionsP[nmax]}] (* Jean-François Alcover, Mar 02 2019 *)
  • PARI
    a(n) = {k=0; while ((pk=numbpart(k)) != n, if (pk > n, return(0)); k++); return (1);} \\ Michel Marcus, Nov 03 2015
    

Formula

a(A000041(n)) = 1; a(A167376(n)) = 0.

A167377 Complement of the range of A000009.

Original entry on oeis.org

0, 7, 9, 11, 13, 14, 16, 17, 19, 20, 21, 23, 24, 25, 26, 28, 29, 30, 31, 33, 34, 35, 36, 37, 39, 40, 41, 42, 43, 44, 45, 47, 48, 49, 50, 51, 52, 53, 55, 56, 57, 58, 59, 60, 61, 62, 63, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88
Offset: 1

Views

Author

Reinhard Zumkeller, Nov 03 2009

Keywords

Comments

A167393(a(n)) = 0.

Crossrefs

Programs

  • Haskell
    import Data.List.Ordered (minus)
    a167377 n = a167377_list !! n
    a167377_list = minus [0..] a000009_list
    -- Reinhard Zumkeller, Nov 03 2015

A072246 Numbers which are simultaneously the number of partitions of some k and the number of distinct partitions of some m.

Original entry on oeis.org

1, 2, 3, 5, 15, 22
Offset: 1

Views

Author

Robert G. Wilson v, Jul 06 2002

Keywords

Comments

No more terms for all A000041(k) and A000009(m), where k<=1002505 and m<=2000000. - Vaclav Kotesovec, May 29 2018

Crossrefs

Intersection of A000041 and A000009; A368036 and A368037.

Programs

  • Mathematica
    Intersection[ Table[ PartitionsP[n], {n, 1, 5000}], Table[ PartitionsQ[n], {n, 1, 7000}]]

Formula

A167392(a(n))*A167393(a(n)) = 1. [From Reinhard Zumkeller, Nov 03 2009]

Extensions

Perhaps there are no more terms? - N. J. A. Sloane Jul 06 2002
Showing 1-3 of 3 results.