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.

A073336 Total number of square parts in all partitions of n.

Original entry on oeis.org

0, 1, 2, 4, 8, 13, 21, 33, 51, 76, 111, 159, 226, 315, 435, 593, 805, 1077, 1435, 1893, 2486, 3237, 4198, 5405, 6935, 8843, 11235, 14201, 17893, 22437, 28052, 34929, 43371, 53653, 66201, 81410, 99876, 122155, 149063, 181399, 220280, 266811, 322524, 388960
Offset: 0

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Author

Vladeta Jovovic, Aug 22 2002

Keywords

Crossrefs

Programs

  • Maple
    b:= proc(n, i) option remember; `if`(n=0, [1, 0],
          `if`(i<1, [0, 0], add((l->l+[0, `if`(j>0 and issqr(i),
           l[1]*j, 0)])(b(n-i*j, i-1)), j=0..iquo(n, i))))
        end:
    a:= n-> b(n, n)[2] :
    seq(a(n), n=0..60);  # Alois P. Heinz, Feb 19 2013
  • Mathematica
    b[n_, i_] :=  b[n, i] = If[n == 0, {1, 0}, If[i<1, {0, 0}, Sum[Function[{l}, l+{0, If[j>0 && IntegerQ[Sqrt[i]], l[[1]]*j, 0]}][b[n-i*j, i-1]], {j, 0, Quotient[n, i]}]]]; a[n_] := b[n, n][[2]]; Table[a[n], {n, 0, 60}] (* Jean-François Alcover, May 13 2015, after Alois P. Heinz *)

Formula

a(n) = Sum_{k=1..n} A046951(k)*A000041(n-k).
G.f.: Sum_{i>=1} x^(i^2)/(1 - x^(i^2)) / Product_{j>=1} (1 - x^j). - Ilya Gutkovskiy, Jan 24 2017

Extensions

More terms from Emeric Deutsch, Nov 18 2004
a(0) inserted by Alois P. Heinz, Feb 19 2013