A082457 a(n) = gcd(1+2n, A057643(1+2n)).

1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 15, 1, 1, 3, 1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 3, 1, 1, 1, 1, 1, 3, 1, 7, 1, 5, 1, 3, 1, 1, 3, 1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 15, 1, 1, 3, 1, 5, 1, 1, 1, 9, 1, 1, 3, 1, 1, 3, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 7, 1, 1, 15, 1, 1, 1, 1, 1, 3, 1, 1

Offset: 1

Author

Labos Elemer, Apr 25 2003

Keywords

• nonn

Comments

This and A066715 are mostly equal; for differences see A083344.

Examples

			n=22: 2n+1=45, A057643(45)=5520, a(22)=gcd(45,5520)=15 while A066715(45)=3.
		

Crossrefs

Cf. A057643, A066715, A000203, A083344.

Programs

Mathematica

di[x_] := Apply[LCM, Divisors[x]+1] Table[GCD[2*w+1, di[1+2*w]], {w, 1, 2048}];