A123702 a(1)=a(2)=1. For n >= 3, a(n) = (product{k=1 to n-1} a(k)) - (sum{j=1 to n-1} a(j)).
1, 1, -1, -2, 3, 4, 18, 408, 175824, 30989858688, 960376803619751958528, 922323604960653729254933704147036248735744, 850680832267616036448642743307003648114050501920269009809993262836200003241653567488
Offset: 1
Crossrefs
Cf. A123703.
Programs
-
Mathematica
f[l_List] := Append[l, Times @@ l - Plus @@ l];Nest[f, {1, 1}, 11] (* Ray Chandler, Oct 09 2006 *)
Formula
For n >= 5, a(n) = a(n-1) a(n-2) (a(n-1)-1) /(a(n-2)-1).
Extensions
Extended by Ray Chandler, Oct 09 2006
Comments