E.g.f.: Sum_{k>=1} (1 - sech(x^k)) (even powers only).
A331338
E.g.f.: Sum_{k>=1} (1 - sech(x^k)) (even powers only).
Terms
- a(0) =1a(1) =7a(2) =421a(3) =10375a(4) =1864921a(5) =177588115a(6) =43788506581
External references
- oeis: A331338
A331338
E.g.f.: Sum_{k>=1} (1 - sech(x^k)) (even powers only).