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 A286912 #17 Feb 16 2025 08:33:45 %S A286912 0,1,1,1,7,1,2,43,43,2,3,277,969,277,3,5,1777,23663,23663,1777,5,8, %T A286912 11407,571099,2180738,571099,11407,8,13,73219,13807469,198906617, %U A286912 198906617,13807469,73219,13,21,469981,333735575,18169793971,68534828391,18169793971,333735575,469981,21 %N A286912 Array read by antidiagonals: T(m,n) = number of edge covers in the grid graph P_m X P_n. %H A286912 Andrew Howroyd, <a href="/A286912/b286912.txt">Table of n, a(n) for n = 1..276</a> %H A286912 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/EdgeCover.html">Edge Cover</a> %H A286912 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/GridGraph.html">Grid Graph</a> %e A286912 Table starts: %e A286912 ====================================================================== %e A286912 m\n| 1 2 3 4 5 6 %e A286912 ---|------------------------------------------------------------------ %e A286912 1 | 0 1 1 2 3 5 ... %e A286912 2 | 1 7 43 277 1777 11407 ... %e A286912 3 | 1 43 969 23663 571099 13807469 ... %e A286912 4 | 2 277 23663 2180738 198906617 18169793971 ... %e A286912 5 | 3 1777 571099 198906617 68534828391 23650967140325 ... %e A286912 6 | 5 11407 13807469 18169793971 23650967140325 30833670159649637 ... %e A286912 ... %Y A286912 Rows 1-3 are A000045(n-1), A286911, A288031. %Y A286912 Main diagonal is A286913. %Y A286912 Cf. A210662, A099390, A089934, A218354. %K A286912 nonn,tabl %O A286912 1,5 %A A286912 _Andrew Howroyd_, May 15 2017 %E A286912 T(1,1) corrected by _Andrew Howroyd_, Jun 04 2017