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.

A088887 Number of different prime signatures of the m values when A056239(m) is equal to n.

Original entry on oeis.org

1, 1, 2, 3, 5, 5, 10, 10, 16, 18, 24, 27, 41, 42, 54, 63, 82, 88, 114, 123, 153, 169, 205, 224, 279, 296, 356, 389, 463, 499, 592, 638, 750, 803, 939, 996, 1173, 1253, 1441, 1543, 1772, 1891, 2158, 2305, 2619, 2780, 3166, 3358, 3805, 4026, 4522, 4810, 5405
Offset: 0

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Author

Naohiro Nomoto, Nov 28 2003

Keywords

Comments

Cardinality of set of multisets of multiplicities of parts of all partitions of n. - Vladeta Jovovic, May 25 2008

Examples

			a(7) = 10: [1], [7], [1,1], [1,2], [1,3] [1,4], [1,5], [2,3], [1,1,1], [1,1,2].
		

Crossrefs

Cf. A088314.

Programs

  • Maple
    b:= proc(n, i) option remember; `if`(n=0, {[]}, `if`(i<1, {},
          {b(n, i-1)[], seq(map(x->sort([x[], j]),
                        b(n-i*j, i-1))[], j=1..n/i)}))
        end:
    a:= n-> nops(b(n, n)):
    seq(a(n), n=0..50);  # Alois P. Heinz, Feb 19 2013
  • Mathematica
    a[n_] := Sort /@ ((Length /@ Split[#])& /@ IntegerPartitions[n]) // Union // Length;
    a /@ Range[0, 50] (* Jean-François Alcover, Oct 31 2020 *)
  • Python
    from sympy.utilities.iterables import partitions
    def A088887(n): return len({tuple(sorted(p.values())) for p in partitions(n)}) # Chai Wah Wu, Sep 10 2023

Extensions

More terms from Vladeta Jovovic, May 25 2008