A233933 Smallest number k such that R(n) is the n-th divisor of k, where R(n) is the n-th Ramanujan prime (A104272).

11, 34, 116, 246, 752, 708, 4288, 1704, 3492, 4848, 11556, 7620, 28608, 47112, 24048, 21480, 45612, 40860, 54960, 218088, 180684, 121464, 94680, 242100, 269760, 486288, 313488, 249840, 376920, 308280, 738540, 721800, 515340, 1106160, 930960, 935280, 737520

Offset: 2

Author

Michel Lagneau, Dec 18 2013

Keywords

• nonn

Examples

			a(2) = 11 because the divisors of 11 are {1, 11}, and the 2nd divisor of 11 is 11 = A104272(2);
a(3) = 34 because the divisors of 34 are {1, 2, 17, 34}, and the 3rd divisor of 34 is 17 = A104272(3).
		

Crossrefs

Cf. A104272, A221647.

Programs

Mathematica

nn=20; R=Table[0,{nn}]; s=0; Do[If[PrimeQ[k],s++]; If[PrimeQ[k/2],s--]; If[sT. D. Noe adapted for this sequence - see A104272 and A221647 *)