OFFSET
1,1
LINKS
Vaclav Kotesovec, Plot of a(n)/(n*2^n) for n = 1..100000
Eric Weisstein's World of Mathematics, Divisor Function
MATHEMATICA
Accumulate[Table[2^k*DivisorSigma[1, k], {k, 1, 30}]]
CROSSREFS
KEYWORD
nonn
AUTHOR
Vaclav Kotesovec, Mar 18 2019
STATUS
approved