A224494 Smallest k such that k*2*p(n)^2+1=q is prime and k*2*q^2+1 is also prime.

5, 2, 29, 41, 9, 2, 71, 30, 32, 6, 35, 11, 6, 50, 2, 20, 9, 120, 56, 21, 9, 75, 90, 51, 51, 29, 107, 9, 74, 155, 116, 11, 29, 86, 116, 35, 200, 12, 11, 39, 9, 105, 51, 422, 36, 65, 6, 32, 27, 44, 9, 41, 14, 116, 266, 41, 29, 5, 50, 95, 27, 71, 69, 330, 21, 194

Offset: 1

Author

Pierre CAMI, Apr 08 2013

Keywords

• nonn

Links

• Pierre CAMI, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A224489, A224490, A224491, A224492, A224493, A224495, A224496.

Programs

Mathematica

a[n_] := For[k = 1, True, k++, p = Prime[n]; If[PrimeQ[q = k*2*p^2 + 1] && PrimeQ[k*2*q^2 + 1], Return[k]]]; Table[ a[n] , {n, 1, 66}] (* Jean-François Alcover, Apr 12 2013 *)