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 1-1 of 1 results.

A244395 Number of partitions of n in which the largest summand has frequency 1, the next largest summand has frequency at most 2, the third largest has frequency at most 3, etc.

Original entry on oeis.org

1, 1, 1, 2, 3, 4, 5, 8, 11, 15, 20, 26, 34, 46, 59, 78, 101, 129, 163, 209, 261, 329, 412, 517, 641, 798, 986, 1216, 1493, 1829, 2229, 2721, 3303, 4000, 4841, 5841, 7034, 8458, 10144, 12137, 14512, 17306, 20596, 24483, 29045, 34391, 40680, 48032, 56627, 66666
Offset: 0

Views

Author

David S. Newman, Jul 03 2014

Keywords

Examples

			For n=6 the partitions counted are: 6, 51, 42, 411, 321.
		

Crossrefs

Programs

  • Maple
    b:= proc(n, i, t) option remember; `if`(n=0, 1, `if`(i<1, 0,
          b(n, i-1, t) +add(b(n-i*j, i-1, t+1), j=1..min(t, n/i))))
        end:
    a:= n-> b(n$2, 1):
    seq(a(n), n=0..60);  # Alois P. Heinz, Jul 03 2014
  • Mathematica
    nend = 20;
    For[n = 1, n <= nend, n++,
    count[n] = 0;
    Ip = IntegerPartitions[n];
    For[i = 1, i <= Length[Ip], i++,
    m = Max[Ip[[i]]];
    condition = True;
    Tip = Tally[Ip[[i]]];
    For[j = 1, j <= Length[Tip], j++,
    condition = condition && (Tip[[j]][[2]] <= j)];
    If[condition, count[n]++ (* ; Print[Ip[[i]]] *)]];
    ]
    Table[count[i], {i, 1, nend}]
    (* Second program: *)
    b[n_, i_, t_] := b[n, i, t] = If[n == 0, 1, If[i < 1, 0,
        b[n, i-1, t] + Sum[b[n-i*j, i-1, t+1], {j, 1, Min[t, n/i]}]]];
    a[n_] := b[n, n, 1];
    a /@ Range[0, 60] (* Jean-François Alcover, Jun 06 2021, after Alois P. Heinz *)

Extensions

More terms from Alois P. Heinz, Jul 03 2014
Showing 1-1 of 1 results.