This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A112649 #13 Oct 18 2024 11:42:10
%S A112649 1,3,5,6,9,10,13,17,18,19,21,22,23,24,25,26,27,30,33,35,36,37,38,39,
%T A112649 43,44,46,47,48
%N A112649 Numbers k such that the k-th Mersenne prime exponent is not a Gaussian prime (not 3 mod 4).
%F A112649 {k: A000043(k) <> 3 (mod 4)}.
%t A112649 Select[Range[48], Mod[MersennePrimeExponent[#], 4] != 3 &] (* _Amiram Eldar_, Oct 18 2024 *)
%Y A112649 Cf. A000043, A112648 (complement).
%K A112649 nonn
%O A112649 1,2
%A A112649 _Jorge Coveiro_, Dec 27 2005
%E A112649 Edited by _Don Reble_, Jan 25 2006
%E A112649 a(25)-a(29) from _Amiram Eldar_, Oct 18 2024