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 A005368 M2589 #30 Jan 20 2025 16:25:42 %S A005368 1,0,1,3,6,15,42,109,320,979,3137,10603,37728,140423,546859,2220294, %T A005368 9374309,41059926,186149869,871717073,4208841555,20917405824, %U A005368 106849492793 %N A005368 Occurrences of principal character. %D A005368 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %H A005368 Russell Merris and William Watkins, <a href="https://doi.org/10.1137/0604054">Tensors and graphs</a>, SIAM J. Algebraic Discrete Methods 4 (1983), no. 4, 534-547. %Y A005368 Cf. A259976. %Y A005368 Possibly first differences of A000664 or, equivalently, row n = 2 of A331509. %K A005368 nonn,more %O A005368 0,4 %A A005368 _N. J. A. Sloane_ %E A005368 a(7)-a(17) from _Andrey Zabolotskiy_, Sep 10 2018 %E A005368 a(18)-a(22) from _Sean A. Irvine_, Mar 02 2022