OFFSET
1,4
FORMULA
a(n)=sum(k=1..n, A138196(k) )
MATHEMATICA
kkk = 1; cc = {1, 1, 1}; Do[w = n!/4; kk = Floor[(DivisorSigma[0, w] + 1)/2]; kkk = kkk + kk; AppendTo[cc, kkk], {n, 4, 54}]; cc
CROSSREFS
KEYWORD
nonn
AUTHOR
Artur Jasinski, Mar 31 2012
STATUS
approved