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.

A319140 Total number of binary digits in all partitions of n into distinct parts.

Original entry on oeis.org

1, 2, 5, 6, 11, 17, 23, 30, 44, 60, 76, 102, 128, 166, 214, 264, 327, 413, 502, 618, 759, 917, 1105, 1335, 1598, 1907, 2279, 2702, 3191, 3776, 4436, 5198, 6101, 7113, 8292, 9653, 11188, 12951, 14984, 17277, 19889, 22881, 26248, 30073, 34439, 39320, 44850
Offset: 1

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Author

David S. Newman, Sep 11 2018

Keywords

Examples

			For n = 4 there are 2 partitions into distinct parts in binary they are: 100, 11+1, for a total of 6 binary parts.
		

Crossrefs

Programs

  • Maple
    h:= proc(n) option remember; 1+ilog2(n) end:
    b:= proc(n, i) option remember; `if`(n=0, [1, 0],
          `if`(n>i*(i+1)/2, 0, b(n, i-1)+(p-> p+h(i)
           *[0, p[1]])(b(n-i, min(n-i, i-1)))))
        end:
    a:= n-> b(n$2)[2]:
    seq(a(n), n=1..60);  # Alois P. Heinz, Sep 27 2018
  • Mathematica
    h[n_] := h[n] = 1+Log[2, n] // Floor;
    b[n_, i_] := b[n, i] = If[n == 0, {1, 0}, If[n > i*(i+1)/2, 0, b[n, i-1] + Function[p, p + h[i]*{0, p[[1]]}][b[n-i, Min[n-i, i-1]]]]];
    a[n_] := b[n, n][[2]];
    a /@ Range[1; 60] (* Jean-François Alcover, Sep 28 2019, after Alois P. Heinz *)
  • PARI
    seq(n)={[subst(deriv(p,y), y, 1) | p<-Vec(-1 + prod(k=1, n, 1 + x^k*y^(logint(k,2)+1) + O(x*x^n)))]} \\ Andrew Howroyd, Sep 17 2018