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 A369227 #24 Feb 16 2025 08:34:06
%S A369227 1,1,1,1,1,1,1,3,1,1,1,5,3,1,1,1,17,12,3,1,1,1,44,72,12,3,1,1,1,182,
%T A369227 856,127,12,3,1,1,1,730,17018,3426,127,12,3,1,1,1,4032,531568,221188,
%U A369227 4938,127,12,3,1,1,1,25598
%N A369227 Triangle read by rows: T(n,k) is the number of uniquely colorable simple graphs on n nodes with chromatic number k = 1..n.
%H A369227 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/ChromaticNumber.html">Chromatic Number</a>.
%H A369227 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/SimpleGraph.html">Simple Graph</a>.
%H A369227 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/UniquelyColorableGraph.html">Uniquely Colorable Graph</a>.
%F A369227 T(n,1) = 1.
%F A369227 T(n,2) = A005142(n).
%F A369227 T(n,3) = A348222(n).
%F A369227 T(n,n) = 1.
%F A369227 Sum_{k=1..n} T(n,k) = A369223(n).
%e A369227 Triangle read by rows:
%e A369227 1
%e A369227 1, 1
%e A369227 1, 1, 1
%e A369227 1, 3, 1, 1
%e A369227 1, 5, 3, 1, 1
%e A369227 1, 17, 12, 3, 1, 1
%e A369227 1, 44, 72, 12, 3, 1, 1
%e A369227 1, 182, 856, 127, 12, 3, 1, 1
%e A369227 1, 730, 17018, 3426, 127, 12, 3, 1, 1
%e A369227 1, 4032, 531568, 221188, 4938, 127, 12, 3, 1, 1
%e A369227 1, 25598, ...
%Y A369227 Cf. A005142, A348222, A369223.
%K A369227 nonn,tabl,more
%O A369227 1,8
%A A369227 _Eric W. Weisstein_, Jan 16 2024