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 A216056 #12 Sep 11 2012 23:24:47 %S A216056 234781,115480283 %N A216056 Primes p such that p divides the numerator of Sum( k!/2^k, k=1..p-1 ). %H A216056 B. M. M. de Weger, <a href="https://listserv.nodak.edu/cgi-bin/wa.exe?A2=NMBRTHRY;5a41ecf9.1208">Sums with factorials</a>, NMBRTHRY list, Aug 28 2012 %Y A216056 Cf. A215972, A215974, A057245 %K A216056 bref,nonn,more %O A216056 1,1 %A A216056 _N. J. A. Sloane_, Aug 30 2012