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.

A088880 Number of different values of A000005(m) when A056239(m) is equal to n.

Original entry on oeis.org

1, 1, 2, 2, 5, 4, 8, 6, 12, 10, 16, 13, 25, 18, 28, 25, 40, 32, 51, 40, 62, 51, 76, 62, 99, 77, 112, 92, 138, 109, 165, 130, 189, 153, 220, 178, 267, 208, 292, 240, 347, 274, 397, 315, 445, 361, 512, 407, 591, 464, 647, 524, 746, 588, 830, 664, 928, 746, 1034
Offset: 0

Views

Author

Naohiro Nomoto, Nov 28 2003

Keywords

Comments

Number of distinct values of Product_{k=1..n} (m(k,P)+1) where m(k,P) is multiplicity of part k in partition P, as P ranges over all partitions of n. - Vladeta Jovovic, May 24 2008

Crossrefs

Programs

  • Maple
    multipl := proc(P,p)
            local a;
            a := 0 ;
            for el in P do
                    if el = p then
                            a := a+1 ;
                    end if;
            end do;
            a ;
    end proc:
    A088880 := proc(n)
            local pro,pa,m,p;
            pro := {} ;
            for pa in combinat[partition](n) do
                    m := 1 ;
                    for p from 1 to n do
                            m := m*(1+multipl(pa,p)) ;
                    end do:
                    pro := pro union {m} ;
            end do:
            nops(pro) ;
    end proc: # R. J. Mathar, Sep 27 2011
    # second Maple program
    b:= proc(n, i) option remember; `if`(n=0 or i<2, {n+1},
           {seq(map(p->p*(j+1), b(n-i*j, i-1))[], j=0..n/i)})
        end:
    a:= n-> nops(b(n, n)):
    seq(a(n), n=0..50);  # Alois P. Heinz, Aug 09 2012
  • Mathematica
    b[n_, i_] := b[n, i] = If[n==0 || i<2, {n+1}, Table[b[n-i*j, i-1]*(j+1), {j, 0, n/i}] // Flatten // Union]; a[n_] := Length[b[n, n]]; Table[a[n], {n, 0, 50}] (* Jean-François Alcover, Jan 08 2016, after Alois P. Heinz *)