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 A378938 #7 Dec 20 2024 10:45:03 %S A378938 1,1,1,1,2,1,1,3,3,1,1,4,8,4,1,1,5,17,17,5,1,1,6,38,52,38,6,1,1,7,78, %T A378938 160,160,78,7,1,1,8,164,469,824,469,164,8,1,1,9,332,1337,3501,3501, %U A378938 1337,332,9,1,1,10,680,3750,16262,22144,16262,3750,680,10,1 %N A378938 Array read by antidiagonals: T(m,n) is the number of Hamiltonian paths in an m X n grid which start in the top left corner. %C A378938 These paths are also called Greek-key tours. The path can end anywhere. %H A378938 Andrew Howroyd, <a href="/A378938/b378938.txt">Table of n, a(n) for n = 1..435</a> (first 29 antidiagonals) %F A378938 T(m,n) = T(n,m). %e A378938 Array begins: %e A378938 ====================================================== %e A378938 m\n | 1 2 3 4 5 6 7 8 ... %e A378938 ----+------------------------------------------------- %e A378938 1 | 1 1 1 1 1 1 1 1 ... %e A378938 2 | 1 2 3 4 5 6 7 8 ... %e A378938 3 | 1 3 8 17 38 78 164 332 ... %e A378938 4 | 1 4 17 52 160 469 1337 3750 ... %e A378938 5 | 1 5 38 160 824 3501 16262 68591 ... %e A378938 6 | 1 6 78 469 3501 22144 144476 899432 ... %e A378938 7 | 1 7 164 1337 16262 144476 1510446 13506023 ... %e A378938 8 | 1 8 332 3750 68591 899432 13506023 180160012 ... %e A378938 ... %Y A378938 Main diagonal is A145157. %Y A378938 Rows 1..8 are A000012, A000027, A046994, A046995, A145156, A160240, A160241, A374307. %Y A378938 Cf. A332307, A064298, A271465, A271592, A288518. %K A378938 nonn,tabl %O A378938 1,5 %A A378938 _Andrew Howroyd_, Dec 20 2024