|
%I #17 Jun 17 2018 09:46:41
%S 242590,1175444,2416288,2583146,2596049,2796151,4953911,5574794,
%T 6127655,6396209,6460877,6625438,8521234,11025856,11352491,15482298,
%U 16228703,18861024,19048003,20043534,22835193,31519781,34399756
%N Prime octets: numbers k such that 210*k - 105 +- 2^j are prime for all 1 <= j <= 4.
%H Harry J. Smith, <a href="/A066082/b066082.txt">Table of n, a(n) for n = 1..100</a>
%e a(1)=242590 because 210*a(1) - 105 = 50943795 and 50943795 -2, - 4, - 8, - 16, + 2, + 4, + 8 and + 16 are all prime.
%t With[{c=2^Range[4]},Select[Range[35*10^6],AllTrue[Flatten[210#-105+ {c,-c}], PrimeQ]&]] (* The program uses the AllTrue function from Mathematica version 10 *) (* _Harvey P. Dale_, Jun 10 2015 *)
%o (PARI) { n=0; for (m=1, 10^12, b=210*m - 105; c=0; for (j=1, 4, if (isprime(b - 2^j) , c++, break)); if (c<4, next); for (j=1, 4, if (isprime(b + 2^j) , c++, break)); if (c == 8, write("b066082.txt", n++, " ", m); if (n==100, return)) ) } \\ _Harry J. Smith_, Nov 11 2009
%Y A proper subset of A061671 (prime sextets). Cf. prime quadruples A014561. See also A066081.
%K nonn
%O 1,1
%A _Frank Ellermann_, Dec 03 2001
%E More terms from _Don Reble_, Dec 07 2001
|
