Expansion of e.g.f. Sum_{k>=1} arctanh(x^k).
A330505
Expansion of e.g.f. Sum_{k>=1} arctanh(x^k).
Terms
- a(0) =1a(1) =2a(2) =8a(3) =24a(4) =144a(5) =960a(6) =5760a(7) =40320a(8) =524160a(9) =4354560a(10) =43545600a(11) =638668800a(12) =6706022400a(13) =99632332800
External references
- oeis: A330505