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A236810
Number of solutions to Sum_{k=1..n} k*c(k) = n! , c(k) >= 0.
12
0, 1, 2, 7, 169, 91606, 2407275335, 4592460368601183, 855163933625625205568537, 20560615981766266405801870502139241, 82864945825700191674729490954631752385038099201, 70899311833745096407560015806403481692583415598602691709750081
OFFSET
0,3
COMMENTS
a(n) is the number of partitions of n! into parts that are at most n. a(3) = 7: [1,1,1,1,1,1], [2,1,1,1,1], [2,2,1,1], [2,2,2], [3,1,1,1], [3,2,1], [3,3]. - Alois P. Heinz, Feb 08 2014
LINKS
P. F. Ayuso, J. M. Grau, A. Oller-Marcen, Von Staudt formula for Sum_{z in Z_n[i]} z^k, arXiv preprint arXiv:1402.0333, 2014, Montsh. Math. 178 (2015) 345-359
Vaclav Kotesovec, Graph - the asymptotic ratio (Total 90 terms were computed with a program by Doron Zeilberger)
A. V. Sills and D. Zeilberger, Formulae for the number of partitions of n into at most m parts (using the quasi-polynomial ansatz), arXiv:1108.4391 [math.CO], Dec 2011
StackExchange, Combinations sum_{k=1..m} k*n_k = m!, Jan 29 2014
FORMULA
a(n) = [x^(n!)] Product_{k=1..n} 1/(1-x^k).
a(n) ~ n * (n!)^(n-3) ~ n^(n^2-5*n/2-1/2) * (2*Pi)^((n-3)/2) / exp(n*(n-3)-1/12). - Vaclav Kotesovec, Jun 05 2015
EXAMPLE
for n=3, the 7 solutions are: 3! = 6,0,0 ; 4,1,0 ; 2,2,0 ; 0,3,0 ; 3,0,1 ; 1,1,1 ; 0,0,2.
MATHEMATICA
Table[Coefficient[Series[Product[1/(1- x^k), {k, n}], {x, 0, n!}], x^(n!)] , {n, 7}]
KEYWORD
nonn
AUTHOR
Wouter Meeussen, Feb 08 2014
EXTENSIONS
a(8)-a(11) from Alois P. Heinz, Feb 08 2014
STATUS
approved