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A222737
Total sum of parts of multiplicity 9 in all partitions of n.
2
1, 0, 1, 1, 2, 2, 4, 4, 7, 10, 14, 16, 25, 30, 42, 53, 71, 88, 121, 148, 195, 241, 312, 384, 494, 605, 765, 943, 1179, 1441, 1796, 2181, 2694, 3273, 4011, 4849, 5922, 7130, 8652, 10398, 12552, 15021, 18072, 21558, 25816, 30729, 36649, 43480, 51705, 61163
OFFSET
9,5
LINKS
FORMULA
G.f.: (x^9/(1-x^9)^2-x^10/(1-x^10)^2)/Product_{i>=1}(1-x^i).
a(n) ~ 19 * sqrt(3) * exp(Pi*sqrt(2*n/3)) / (16200 * Pi^2). - Vaclav Kotesovec, May 29 2018
MAPLE
b:= proc(n, p) option remember; `if`(n=0, [1, 0], `if`(p<1, [0, 0],
add((l->`if`(m=9, l+[0, l[1]*p], l))(b(n-p*m, p-1)), m=0..n/p)))
end:
a:= n-> b(n, n)[2]:
seq(a(n), n=9..60);
MATHEMATICA
b[n_, p_] := b[n, p] = If[n == 0 && p == 0, {1, 0}, If[p == 0, Array[0&, n+2], Sum[Function[l, ReplacePart[l, m+2 -> p*l[[1]] + l[[m+2]]]][Join[b[n-p*m, p-1], Array[0&, p*m]]], {m, 0, n/p}]]]; a[n_] := b[n, n][[11]]; Table[a[n], {n, 9, 60}] (* Jean-François Alcover, Jan 24 2014, after Alois P. Heinz *)
CROSSREFS
Column k=9 of A222730.
Sequence in context: A253412 A291148 A032190 * A005852 A370591 A274625
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Mar 03 2013
STATUS
approved