A248346 - OEIS

%I #37 Apr 30 2022 09:22:15

%S 2,3,7,23,31,47,71,79,103,127,151,199,223,271,367,431,463,487,503,727,

%T 751,823,967,1087,1303,1319,1423,1439,1559,1607,1759,1823,1879,1951,

%U 1999,2039,2143,3343,3527,3623,3967,4447,4943,5167,5503,5591,5791,6199,6343

%N Primes of the form 2^x - y^2, with y^2 < 2^x.

%C Primes in A051213.

%e 7 is in this sequence because 7 = 2^3 - 1^2 = 2^4 - 3^2 = 2^5 - 5^2 = 2^7 - 11^2 = 2^15 - 181^2.

%e 1559 is in this sequence because 1559 = 2^19 - 723^2 is prime. - _Sean A. Irvine_, Apr 28 2022

%t Select[Union[Flatten[Table[2^x - y^2, {x, 16}, {y, 0, Floor[Sqrt[2^x]]}]]], PrimeQ] (* _Alonso del Arte_, Oct 05 2014 *)

%Y Cf. A038198, A051213, A060728, A248344.

%Y Primes in A056007 form a subset of the numbers in this sequence.

%K nonn

%O 1,1

%A _Juri-Stepan Gerasimov_, Oct 05 2014

%E a(24)-a(38) from _Alonso del Arte_, Oct 05 2014

%E More terms and missing terms inserted by _Sean A. Irvine_, Apr 28 2022