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 A342128 #17 Feb 16 2025 08:34:01 %S A342128 0,1,0,2,0,0,3,2,0,0,4,6,2,0,0,5,12,18,2,0,0,6,20,84,114,2,0,0,7,30, %T A342128 260,2652,2970,2,0,0,8,42,630,29660,1321860,1185282,2,0,0,9,56,1302, %U A342128 198030,187430900,130253748108,100301050602,2,0,0,10,72,2408,932862,10199069190,2157531034816940 %N A342128 Table read by antidiagonals upwards: T(n,k) is the number of n-colorings of the vertices of the k-dimensional hypercube such that no two adjacent vertices have the same color. n >= 0, k >=0. %H A342128 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/ChromaticPolynomial.html">Chromatic Polynomial</a> %H A342128 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/HypercubeGraph.html">Hypercube Graph</a> %F A342128 T(n,k) = Sum_{i=0..2^k} A334278(k,i)*n^i. %e A342128 Table begins: %e A342128 n\k| 0 1 2 3 4 5 %e A342128 ---+----------------------------------------------------------------------- %e A342128 0 | 0 0 0 0 0 0 %e A342128 1 | 1 0 0 0 0 0 %e A342128 2 | 2 2 2 2 2 2 %e A342128 3 | 3 6 18 114 2970 1185282 %e A342128 4 | 4 12 84 2652 1321860 130253748108 %e A342128 5 | 5 20 260 29660 187430900 2157531034816940 %e A342128 6 | 6 30 630 198030 10199069190 7905235551766437150 %e A342128 7 | 7 42 1302 932862 269591166222 7365707045872206479742 %e A342128 8 | 8 56 2408 3440024 4221404762120 2337101560809838105414712 %e A342128 9 | 9 72 4104 10599192 44876701584360 327425229254999498091796728 %e A342128 10 | 10 90 6570 28478970 355148098691850 24489214732779742874109277530 %Y A342128 Columns and rows: A002378 (k=1), A091940 (k=2), A140986 (k=3), A158348 (k=4), A380589 (k=5), A307334 (n=3). %Y A342128 Cf. A334278, A342088 (analogous for cross-polytope). %K A342128 nonn,tabl %O A342128 0,4 %A A342128 _Peter Kagey_, Feb 28 2021