A224610 Smallest j such that j*2*prime(n)^3-1 and j*2*prime(n)*q^2-1 are prime.

2, 2, 5, 7, 59, 142, 264, 25, 8, 21, 124, 33, 60, 87, 9, 231, 5, 6, 82, 155, 7, 66, 72, 21, 42, 105, 15, 48, 250, 68, 222, 54, 47, 195, 255, 360, 205, 6, 83, 26, 5, 1, 50, 220, 173, 1, 976, 30, 228, 130, 30, 129, 46, 1106, 65, 62, 15, 109, 24, 41, 922, 15, 132, 89

Offset

1,1

Links

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

Mathematica

a[n_] := For[p = Prime[n]; j = 1, j < 10^6, j++, If[PrimeQ[q = j*2*p^3 - 1] && PrimeQ[j*p*2*q^2 - 1], Return[j]]]; Table[a[n], {n, 1, 75}] (* Jean-François Alcover, Apr 22 2013 *)

Prog

(PFGW & SCRIPTIFY)
SCRIPT
DIM n, 1
DIM j
DIM q
DIMS t
OPENFILEOUT myf, a(n).txt
LABEL a
SET n, n+1
SET j, 0
LABEL b
SET j, j+1
SET q, j*2*p(n)^3-1
SETS t, %d\,; p(n)
PRP q, t
IF ISPRP THEN GOTO c
GOTO b
LABEL c
SET q, j*2*p(n)*q^2-1
PRP q, t
IF ISPRP THEN GOTO d
GOTO b
LABEL d
WRITE myf, t
GOTO a

Crossrefs

Cf. A224490, A224609, A224611, A224612.

Sequence in context: A208818 A221835 A074476 * A265819 A254746 A011021

Adjacent sequences: A224607 A224608 A224609 * A224611 A224612 A224613

Keyword

nonn

Author

Pierre CAMI, Apr 12 2013

Status

approved