A082452 a(n)=2n+1 where n is such that A083344(n) is not zero.

45, 75, 117, 147, 189, 195, 225, 231, 245, 315, 325, 345, 363, 385, 405, 441, 483, 495, 507, 525, 561, 567, 585, 595, 645, 663, 675, 693, 715, 735, 765, 775, 777, 795, 819, 845, 847, 867, 875, 891, 931, 945, 957, 975, 1001, 1035, 1071, 1083, 1089, 1095, 1125

Offset: 1

Author

Labos Elemer, Apr 25 2003

Keywords

• nonn

Examples

			n=22: 2n+1=45, A057643(45)=5520, a(22)=GCD[45,5520]=15 while A066715[45]=3; a(22)=15-3=12.
		

Crossrefs

Cf. A057643, A066715, A000203, A082457, A083344.

Programs

Mathematica

di[x_] := Apply[LCM, Divisors[x]+1] (*A066715=*)t1=Table[GCD[2*n+1, DivisorSigma[1, 2*n+1]], {n, 1, 2048}]; (*A082457=*)t2=Table[GCD[2*w+1, di[1+2*w]], {w, 1, 2048}]; (*A083344=*)t3=t2-t1; (*A082452=*)1+2*Flatten[Position[Abs[Sign[t3]], 1]];