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 A369997 #5 Feb 09 2024 08:43:55 %S A369997 1,1,1,1,1,1,1,1,1,1,3,2,3,1,1,1,1,1,3,4,9,15,31,35,40,24,18,6,4,1,1 %N A369997 Irregular triangle read by rows: T(n,k) is the number of connected induced k-vertex subgraphs, up to isomorphism, of the hypercube graph of dimension n >= 0, 1 <= k <= 2^n. %C A369997 In A369605, two isomorphic subgraphs may both be counted, namely if there is no automorphism of the hypercube graph that takes one to the other. The first difference is T(4,5) = 4 < A369605(4,5) = 5. The path with 5 vertices is an induced subgraph of the 4-dimensional hypercube in two inequivalent ways: one that is contained in a 3-dimensional subcube and one that is not. %e A369997 Triangle begins: %e A369997 1; %e A369997 1, 1; %e A369997 1, 1, 1, 1; %e A369997 1, 1, 1, 3, 2, 3, 1, 1; %e A369997 1, 1, 1, 3, 4, 9, 15, 31, 35, 40, 24, 18, 6, 4, 1, 1; %e A369997 ... %Y A369997 Cf. A369605 (up to automorphisms of the hypercube), A369995 (not necessarily connected subgraphs), A369998 (row sums), A369999. %K A369997 nonn,tabf,more %O A369997 0,11 %A A369997 _Pontus von Brömssen_, Feb 07 2024