A123703 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, 2, 2, 12, 264, 75744, 5758891776, 33165272341980979200, 1099935289708766240667530888404210286592, 1209857641546707521062997518664689369471121315619387834957574646785625397657600

Offset

1,4

Links

Table of n, a(n) for n=1..14.

Mathematica

f[l_List] := Append[l, Abs[Times @@ l - Plus @@ l]]; Nest[f, {1, 1}, 12] (* Ray Chandler, Oct 09 2006 *)

Crossrefs

Cf. A123702.

Sequence in context: A298310 A138680 A171684 * A105436 A266911 A244075

Adjacent sequences: A123700 A123701 A123702 * A123704 A123705 A123706

Keyword

easy,nonn

Author

Leroy Quet, Oct 08 2006

Extensions

Extended by Ray Chandler, Oct 09 2006

Status

approved