A224495 Smallest k such that k*2*p(n)^2+1=q is prime 2*k*q^2+1=r 2*k*r^2+1=s, r and s are also prime.

9, 126, 29, 237, 420, 2, 186, 30, 2349, 896, 1266, 147, 741, 140, 3021, 924, 19571, 896, 791, 11495, 32, 7016, 3522, 5336, 932, 5480, 107, 1439, 1770, 209, 4239, 1716, 477, 1196, 1446, 900, 9176, 1920, 2375, 39, 2351, 590, 2724, 422, 3171, 179, 1751, 426, 65

Offset

1,1

Links

Pierre CAMI, Table of n, a(n) for n = 1..5600

Mathematica

a[n_] := For[k = 1, True, k++, p = Prime[n]; If[PrimeQ[q = k*2*p^2 + 1] && PrimeQ[r = k*2*q^2 + 1] && PrimeQ[k*2*r^2 + 1], Return[k]]]; Table[ a[n] , {n, 1, 49}] (* Jean-François Alcover, Apr 12 2013 *)

Crossrefs

Cf. A224489, A224490, A224492, A224492, A224493, A224494, A224496.

Sequence in context: A078422 A291897 A324201 * A064199 A092343 A261176

Adjacent sequences: A224492 A224493 A224494 * A224496 A224497 A224498

Keyword

nonn

Author

Pierre CAMI, Apr 08 2013

Status

approved