G.f.: exp( Sum_{n>=1} 2*sigma(n*5^n)*x^n/n ).
A193104
G.f.: exp( Sum_{n>=1} 2*sigma(n*5^n)*x^n/n ).
Terms
- a(0) =1a(1) =12a(2) =165a(3) =1820a(4) =19610a(5) =190006a(6) =1823415a(7) =16461130a(8) =146258245a(9) =1254022900a(10) =10573576571a(11) =86961051682a(12) =705575418795
External references
- oeis: A193104