a(0) = 1; for n>0, a(n) = (2^n-1)*a(n-1)-(-1)^n.

A111491

a(0) = 1; for n>0, a(n) = (2^n-1)*a(n-1)-(-1)^n.

Terms

    a(0) =1a(1) =2a(2) =5a(3) =36a(4) =539a(5) =16710a(6) =1052729a(7) =133696584a(8) =34092628919

External references