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A224612
Let p = prime(n). Smallest j such that j*2*p^3-1, j*p*2*q^2-1, j*p*2*r^2-1, and j*p*2*s^2-1 are prime numbers.
3
29952, 12063, 1463, 6102, 11661, 49552, 639179, 2099290, 291248, 393186, 545251, 321303, 436641, 278295, 746832, 237852, 56490, 165901, 152847, 619755, 777177, 3410085, 117513, 2015421
OFFSET
1,1
COMMENTS
Conjecture: a(n) exists for all n.
MATHEMATICA
a[n_] := For[j = 1, j < 10^7, j++, p = Prime[n]; If[PrimeQ[q = j*2*p^3 - 1] && PrimeQ[r = j*2*p*q^2 - 1] && PrimeQ[s = j*2*p*r^2 - 1] && PrimeQ[j*2*p*s^2 - 1], Return[j]]]; Table[Print[an = a[n]]; an, {n, 1, 24}] (* Jean-François Alcover, Apr 12 2013 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Pierre CAMI, Apr 12 2013
EXTENSIONS
More terms from Jean-François Alcover, Apr 12 2013
STATUS
approved