A127078 a(0)=1. a(n) = a(n-1) + (product of the earlier terms {among terms a(0) through a(n-1)} which are coprime to n).

1, 2, 3, 5, 20, 26, 31, 483631, 225372046, 17570301566444363246, 17570301566489340929, 16272673148565174391333181067098727985892644426731405243329

Offset

0,2

Links

Table of n, a(n) for n=0..11.

Example

The terms of the sequence, among terms a(0) through a(5), which are coprime to 6 are a(0)=1 and a(3)=5. So a(6) = a(5) + 1*5 = 31.

Mathematica

f[l_List] := Append[l, l[[ -1]] + Times @@ Select[l, GCD[ #, Length[l]] == 1 &]]; Nest[f, {1}, 13] (* Ray Chandler, Jan 06 2007 *)

Crossrefs

Cf. A127077.

Sequence in context: A048826 A321084 A054798 * A184252 A228833 A320950

Adjacent sequences: A127075 A127076 A127077 * A127079 A127080 A127081

Keyword

nonn

Author

Leroy Quet, Jan 04 2007

Extensions

Extended by Ray Chandler, Jan 06 2007

Status

approved