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 A320837 #12 Feb 16 2025 08:33:56
%S A320837 1,2,2,3,3,4,4,4,4,4,5,4,5,6,6,6,6,7,6,6,7,8,6,6,6,7,7,6,7,7,8,8,8,8,
%T A320837 7,8,8,8,8,8,10,8,10,10,8,8,10,10,8,9,10,10,11,10,10,10,10,10,10,9,9,
%U A320837 10,10,10,10,10,8,10,11,10,12,12,12,10
%N A320837 For p the n-th prime congruent to 1 (mod 4), a(n) is the clique number of the subgraph of the quadratic residue (Paley) graph over F_p, the field of order p, that is induced by the set of vertices that are themselves quadratic residues.
%H A320837 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/CliqueNumber.html">Clique Number</a>
%H A320837 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PaleyGraph.html">Paley Graph</a>
%e A320837 a(1) = 1 because the subgraph of the Paley graph of order 5 induced by {1,4} is the two-vertex empty graph.
%Y A320837 Cf. A002144 (primes of form 4n + 1), A320757.
%K A320837 nonn,more
%O A320837 1,2
%A A320837 _Jeremy F. Alm_, Oct 21 2018