OFFSET
1,2
COMMENTS
a(n) is the sum of (the zeroth moments of) all partitions of n minus the partition number of n.
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
EXAMPLE
a(7) = 90 = (7-1)*15 = 105 - 15, because the number of partitions of 7 is 15 and the sum of all parts of all partitions of 7 is 7*15 = 105.
MAPLE
a:= n-> (n-1) *combinat[numbpart](n):
seq (a(n), n =1..50);
MATHEMATICA
pnxt[n_]:=Module[{ps=IntegerPartitions[n]}, Total[Flatten[ps]]- Length[ps]]; Array[pnxt, 40] (* Harvey P. Dale, Jul 15 2011 *)
Table[(n-1)PartitionsP[n], {n, 40}] (* Harvey P. Dale, Jan 17 2015 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Omar E. Pol, Jan 30 2011
STATUS
approved