a(n) = (-1)^n * coefficient of x^n in Sum_{k>=1} x^(k-1)/(1+4*x^k).

A101562

a(n) = (-1)^n * coefficient of x^n in Sum_{k>=1} x^(k-1)/(1+4*x^k).

Terms

    a(0) =1a(1) =3a(2) =17a(3) =67a(4) =257a(5) =1011a(6) =4097a(7) =16451a(8) =65553a(9) =261891a(10) =1048577a(11) =4195379a(12) =16777217a(13) =67104771a(14) =268435729a(15) =1073758275a(16) =4294967297a(17) =17179804659a(18) =68719476737a(19) =274878168899

External references