a(1) = 1; a(n) = sigma(n) - sigma(n-1)* a(n-1) if n > 1.

A079897

a(1) = 1; a(n) = sigma(n) - sigma(n-1)* a(n-1) if n > 1.

Terms

    a(0) =1a(1) =2a(2) =-2a(3) =15a(4) =-99a(5) =606a(6) =-7264a(7) =58127a(8) =-871892a(9) =11334614a(10) =-204023040a(11) =2448276508a(12) =-68551742210a(13) =959724390964

External references