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 A350958 #7 Feb 05 2022 23:32:10 %S A350958 1,18,33,39,48,60,63,72,78,81,93,102,105,108,111,138,144,150,153,162, %T A350958 164,165,168,171,183,186,189,198,204,207,213,219,228,237,243,249,258, %U A350958 264,267,270,273,276,281,288,291,303,306,312,315,318,333,336,345,348,354,357 %N A350958 Positive numbers k such that 2k cannot be written as 3^i (i >= 0) plus a prime. %C A350958 A058517 halved. %Y A350958 Cf. A006285, A058517, A350628-A350630, A350957. %K A350958 nonn %O A350958 1,2 %A A350958 _N. J. A. Sloane_, Feb 05 2022