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 A309675 #31 Aug 24 2019 12:20:39 %S A309675 2,5,258,262150,4294967320,1125899906842744,4722366482869645214416, %T A309675 316912650057057350374175806384, %U A309675 340282366920938463463374607431768251776,5846006549323611672814739330865132078623730534784,1606938044258990275541962092341162602522202993782792838930176 %N A309675 a(n) = 4^n^2 + n!. %H A309675 Andrew M. Kamal, <a href="https://mentors4edu.github.io/New-Field/">New Field</a> %e A309675 a(1) = 5 since 1^1=1, (4^1) + 1! = 5; %e A309675 a(2) = 4^2^2 = 4^4 = 256, 256 + 2! = 256 + 2*1 = 258. %Y A309675 Cf. A309669, A192366. %K A309675 nonn %O A309675 0,1 %A A309675 _Andrew M. Kamal_, Aug 11 2019