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 1-2 of 2 results.

A067694 Minimum number of distinct parts in a self-conjugate partition of n, or 0 if n=2.

Original entry on oeis.org

0, 1, 0, 2, 1, 2, 3, 2, 2, 1, 3, 2, 2, 2, 3, 2, 1, 2, 3, 2, 2, 2, 3, 2, 2, 1, 3, 2, 2, 2, 3, 2, 2, 2, 3, 2, 1, 2, 3, 2, 2, 2, 3, 2, 2, 2, 3, 2, 2, 1, 3, 2, 2, 2, 3, 2, 2, 2, 3, 2, 2, 2, 3, 2, 1, 2, 3, 2, 2, 2, 3, 2, 2, 2, 3, 2, 2, 2, 3, 2, 2, 1, 3, 2, 2, 2, 3, 2, 2, 2, 3, 2, 2, 2, 3, 2, 2, 2, 3, 2, 1, 2, 3
Offset: 0

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Author

Naohiro Nomoto, Feb 05 2002

Keywords

Comments

There are no self-conjugate partitions of 2, so we set a(2)=0.

Crossrefs

Programs

  • Mathematica
    a[0]=a[2]=0; a[n_] := Which[IntegerQ[Sqrt[n]], 1, Mod[n, 4]==2, 3, True, 2]
  • PARI
    A067694(n) = if((2==n)||!n,0,if(2==(n%4),3,if(issquare(n),1,2))); \\ Antti Karttunen, Sep 27 2018

Formula

a(0)=a(2)=0; a(n^2)=1; a(4n+2)=3 for n>0; a(n)=2 in all other cases.

Extensions

Edited by Dean Hickerson, Feb 15 2002

A240450 Greatest number of distinct numbers in the intersection of p and its conjugate, as p ranges through the partitions of n.

Original entry on oeis.org

2, 1, 3, 2, 3, 4, 3, 4, 3, 5, 4, 5, 4, 5, 6, 5, 6, 5, 6, 5, 7, 6, 7, 6, 7, 6, 7, 8, 7, 8, 7, 8, 7, 8, 7, 9, 8, 9, 8, 9
Offset: 1

Views

Author

Clark Kimberling, Apr 12 2014

Keywords

Comments

Number of terms in row n of the array at A240181.
To match the definition, all terms need to be decreased by 1 (because the rows in A240181 start with k=0). So this appears to be an incorrect duplicate of A067731. - Joerg Arndt, Jul 30 2017

Crossrefs

Programs

  • Mathematica
    z = 30; conjugatePartition[part_] := Table[Count[#, _?(# >= i &)], {i, First[#]}] &[part]; c = Map[BinCounts[#, {0, 1 + Max[#]}] &[Map[Length, Map[Intersection[#, conjugatePartition[#]] &, IntegerPartitions[#]]]] &, Range[z]]; Flatten[c]  (* A240181 *)
    Table[Length[c[[n]]], {n, 1, z}] (* A240450 *) (* Peter J. C. Moses, Apr 10 2014 *)
Showing 1-2 of 2 results.