A276432 Sum of the traces of all plane partitions of n.
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
Keywords
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.
Links
- Vaclav Kotesovec, Table of n, a(n) for n = 1..10000
Programs
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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
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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).
Comments