OFFSET
1,2
COMMENTS
Sum of all parts > 1 of the last section of the set of partitions of n.
Partial sums give A194552. - Omar E. Pol, Sep 23 2013
LINKS
Vaclav Kotesovec, Table of n, a(n) for n = 1..10000
FORMULA
a(n) ~ Pi^2/6*A000070(n-2). - Peter Bala, Dec 23 2013
G.f.: x*f'(x), where f(x) = Product_{k>=2} 1/(1 - x^k). - Ilya Gutkovskiy, Apr 13 2017
a(n) ~ Pi * exp(sqrt(2*n/3)*Pi) / (12*sqrt(2*n)) * (1 - (3*sqrt(3/2)/Pi + 13*Pi/(24*sqrt(6)))/sqrt(n) + (217*Pi^2/6912 + 9/(2*Pi^2) + 13/8)/n). - Vaclav Kotesovec, Jul 06 2019
MATHEMATICA
Table[Total[Flatten[Select[IntegerPartitions[n], FreeQ[#, 1]&]]], {n, 50}] (* Harvey P. Dale, May 24 2015 *)
a[n_] := (PartitionsP[n] - PartitionsP[n-1])*n; Table[a[n], {n, 1, 50}] (* Jean-François Alcover, Oct 07 2015 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Omar E. Pol, Apr 30 2008
EXTENSIONS
Better definition from Omar E. Pol, Sep 23 2013
STATUS
approved