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 A007643 M5274 #21 Oct 13 2019 11:20:48 %S A007643 41,43,53,59,67,71,83,89,97,103,107,109,113,131,137,149,151,157,163, %T A007643 167,173,181,191,193,197,199,223,233,251,257,263,271,277,281,283,293, %U A007643 307,311,313,317,331,337,347,349,353,359,367,373,379,383,389 %N A007643 Primes not of form | 3^x - 2^y |. %D A007643 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %H A007643 H. Gauchman and I. Rosenholtz (Proposers), R. Martin (Solver), <a href="https://www.jstor.org/stable/2691457">Difference of prime powers, Problem 1404</a>, Math. Mag., 65 (No. 4, 1992), 265; <a href="https://www.jstor.org/stable/2690747">Solution</a>, Math. Mag., 66 (No. 4, 1993), 269. %Y A007643 Cf. A007644, A004051, A103146. %K A007643 nonn %O A007643 1,1 %A A007643 _N. J. A. Sloane_, _Mira Bernstein_, _Robert G. Wilson v_