A260354 - OEIS

%I #13 Sep 08 2022 08:46:13

%S 0,1,2,3,4,5,6,7,8,18,28,29,41,69,94,151,189,276,277,290,367,497,578,

%T 579,580,617,618,619,620,744,810,887,903,939,1048,1049,1108,1124,1125,

%U 1172,1303,1304,1305,1399,1420,1449,1614,1761,1790,1838,1861,1865,1971

%N Numbers n such that 2*n^2+11, 2*(n+1)^2+11 and 2*(n+2)^2+11 are prime.

%C n, n+1 and n+2 are terms in A092968, i.e., n and n+1 are terms in A260352.

%H Zak Seidov, <a href="/A260354/b260354.txt">Table of n, a(n) for n = 1..10000</a>

%t Select[Range[0, 2000], PrimeQ[2 #^2 + 11] && PrimeQ[2 (# + 1)^2 + 11] && PrimeQ[2 (# + 2)^2 + 11] &] (* _Vincenzo Librandi_, Jul 26 2015 *)

%o (Magma) [n: n in [0..3000]| IsPrime( 2*n^2+11) and IsPrime(2*(n+1)^2+11) and IsPrime(2*(n+2)^2+11)]; // _Vincenzo Librandi_, Jul 26 2015

%Y Subsequence of A260352 and A092968.

%K nonn,easy

%O 1,3

%A _Zak Seidov_, Jul 23 2015