|
%I #6 Oct 15 2013 22:32:23
%S 13,4133,1831343,2320583,3828673,9173893,23658377,24037537,42489677,
%T 56253203,78222863,96325093,99846337,110453773,110468653,117748427,
%U 122173187,130937467,138072163,146981537,174978913,184050553,186927817
%N Primes p for which 2^j+p^j is also prime for j in {0,2,8,512}.
%e Smallest such prime is 13 and the relevant four primes are
%e 2, 173, 815730977 and a 571-digit prime.
%t {ta=Table[0, {100}], u=1}; {exponents, {a, b, c, d}={0, 2, 8, 512}} Do[s0=Prime[j]^a+2^a;s1=Prime[j]^b+2^b;s2=Prime[j]^c+2^c;s3=Prime[j]^d+2^d; If[PrimeQ[s0]&&PrimeQ[s1]&&PrimeQ[s2]&&PrimeQ[s3], Print[{j, Prime[j]}];ta[[u]]=Prime[j];u=u+1], {j, 1, 1000000}] ta
%Y Cf. A082101, A094473-A094499.
%K nonn
%O 1,1
%A _Labos Elemer_, Jun 02 2004
%E a(6)-a(23) from _Donovan Johnson_, Oct 12 2008
|
