G.f.: exp( Sum_{n>=1} (sigma(2*n) - sigma(n))*Lucas(n)*x^n/n ), where Lucas(n) = A000204(n) and sigma(n) = A000203(n) is the sum of divisors of n.
A225524
G.f.: exp( Sum_{n>=1} (sigma(2*n) - sigma(n))*Lucas(n)*x^n/n ), where Lucas(n) = A000204(n) and sigma(n) = A000203(n) is the sum of divisors of n.
Terms
- a(0) =1a(1) =2a(2) =8a(3) =24a(4) =66a(5) =184a(6) =488a(7) =1248a(8) =3136a(9) =7776a(10) =18780a(11) =44880a(12) =105896a(13) =246124a(14) =567008a(15) =1293840a(16) =2920626a(17) =6545352a(18) =14555388a(19) =32115120a(20) =70421792a(21) =153451488a(22) =332314512a(23) =715843200a(24) =1534016392a(25) =3270661294a(26) =6941489040a(27) =14667591672a(28) =30859685088a(29) =64670865304
External references
- oeis: A225524