a(n) = numerator of b(n), where b(1) = 1, b(n+1) = Sum_{k=1..n} b(k)^((-1)^(n-k+1)).

A115601

a(n) = numerator of b(n), where b(1) = 1, b(n+1) = Sum_{k=1..n} b(k)^((-1)^(n-k+1)).

Terms

    a(0) =1a(1) =1a(2) =2a(3) =5a(4) =22a(5) =115a(6) =1034a(7) =10925a(8) =197494a(9) =4184275a(10) =151477898a(11) =6422862125a(12) =465188624758

External references