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 A220450 #7 Dec 02 2021 18:26:24 %S A220450 1,1,9,10,0,11,11,2,6,12,15,9,0,17,15,4,1,17,2,17,17,1,18,0,16,16,15, %T A220450 7,14,8,1,0,4,8,11,17,4,15,4,4,17,2,0,6,6,8,5,10,3,17,0,11,3,16,4,11, %U A220450 8,11,11,4,15,0,7,7,3,9,18,13,4,0,16,13,6,11,16,3,16,16,11,8,0,5,5,13,1,2,12 %N A220450 a(n) = A220449(n) mod 19. %H A220450 V. H. Moll, <a href="http://www.tulane.edu/~vhm/papers_html/xn-final.pdf">An arithmetic conjecture on a sequence of arctangent sums</a>, 2012. %Y A220450 Cf. A220449. %K A220450 nonn %O A220450 1,3 %A A220450 _N. J. A. Sloane_, Dec 22 2012