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 A014547 #26 Feb 16 2025 08:32:33 %S A014547 2,3,19,227,255 %N A014547 n-th Euler (secant, zig) number A000364(n) is prime. %H A014547 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/EulerNumber.html">Euler Number.</a> %H A014547 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/IntegerSequencePrimes.html">Integer Sequence Primes</a> %t A014547 Select[Range[100], PrimeQ[EulerE[#]] &]/2 (* _Harvey P. Dale_, Aug 10 2011 *) %Y A014547 Cf. A000364. %K A014547 more,nonn %O A014547 1,1 %A A014547 _Eric W. Weisstein_ %E A014547 Offset corrected by _Arkadiusz Wesolowski_, Oct 17 2011