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.

A276432 Sum of the traces of all plane partitions of n.

Original entry on oeis.org

1, 4, 10, 26, 56, 126, 252, 512, 980, 1866, 3427, 6258, 11121, 19618, 33975, 58328, 98732, 165804, 275246, 453544, 740338, 1200088, 1929897, 3083898, 4893775, 7720826, 12106814, 18883104, 29291740, 45215386, 69451631, 106197524, 161656759, 245050410, 369935066
Offset: 1

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Author

Emeric Deutsch, Sep 24 2016

Keywords

Comments

Convolution of A000203 and A000219. - Vaclav Kotesovec, Sep 25 2016
Convolution of A340793 and A091360. - Omar E. Pol, Feb 16 2021

Examples

			a(3) = 10 because the 6 (=A000219(3)) planar partitions of 3 are [3], [2,1], [2;1], [1,1,1], [1;1;1], [1,1;1] (; indicates a new row); the sum of their traces is 3+2+2+1+1+1 = 10.
		

References

  • G. E. Andrews, The Theory of Partitions, Addison-Wesley, 1976, pp. 179-201.

Crossrefs

Programs

  • Maple
    g:= (sum(j*x^j/(1-x^j),j = 1..100))/(product((1-x^k)^k,k = 1..100)): gser := series(g, x = 0,40): seq(coeff(gser, x, m), m = 1 .. 35);
    # second Maple program:
    b:= proc(n, i) option remember; `if`(n=0, [1, 0], `if`(i<1, 0, add((p
          ->p+[0, j*p[1]])(b(n-i*j, i-1))*binomial(i+j-1, j), j=0..n/i)))
        end:
    a:= n-> b(n$2)[2]:
    seq(a(n), n=1..50);  # Alois P. Heinz, Sep 24 2018
  • Mathematica
    nmax = 50; Rest[CoefficientList[Series[Sum[j*x^j/(1-x^j), {j, 1, nmax}]*Product[1/(1-x^k)^k, {k, 1, nmax}], {x, 0, nmax}], x]] (* Vaclav Kotesovec, Sep 25 2016 *)

Formula

G.f.: g(x) = Sum_{j>=1} (j*x^j/(1-x^j))/Product_{k>=1} (1-x^k)^k.
a(n) = Sum(k*A089353(n,k), k>=1).