login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Numbers n such that 90*n + 47 and 90*n + 49 are twin primes.
1

%I #16 Oct 18 2015 12:33:16

%S 1,2,9,16,18,22,29,38,39,43,50,51,87,95,107,108,109,111,121,123,134,

%T 137,143,144,155,160,162,176,178,193,195,199,200,227,230,233,237,239,

%U 240,241,247,248,251,261,262,277,304,314,324,326,328,338,339,352,363,370

%N Numbers n such that 90*n + 47 and 90*n + 49 are twin primes.

%C All matching entries for A201734 and A201818 are twin primes.

%H Harvey P. Dale, <a href="/A224859/b224859.txt">Table of n, a(n) for n = 1..1000</a>

%F A201734 intersect A201818.

%t Select[Range[0, 499], PrimeQ[90# + 47] && PrimeQ[90# + 49] &] (* copied from: _Alonso del Arte_, Jul 22 2013 *)

%t Select[Range[500],AllTrue[90#+{47,49},PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* _Harvey P. Dale_, Oct 18 2015 *)

%Y Cf. A201734, A201818.

%K nonn

%O 1,2

%A _J. W. Helkenberg_, Jul 22 2013