G.f.: A(x) = exp( Sum_{n>=1} 2*sigma(n,n-1)*x^n/n ).
A158095
G.f.: A(x) = exp( Sum_{n>=1} 2*sigma(n,n-1)*x^n/n ).
Terms
- a(0) =1a(1) =2a(2) =5a(3) =14a(4) =61a(5) =370a(6) =3454a(7) =40880a(8) =614346a(9) =10848514a(10) =222870183a(11) =5175100204a(12) =134514302384
External references
- oeis: A158095