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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. 4
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 (list; graph; refs; listen; history; text; internal format)
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-Fran├žois 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

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Last modified February 27 04:56 EST 2020. Contains 332299 sequences. (Running on oeis4.)