A286870 Array read by antidiagonals: T(m,n) = number of irredundant sets in the m X n king graph.
2, 3, 3, 5, 5, 5, 9, 11, 11, 9, 15, 25, 43, 25, 15, 26, 51, 133, 133, 51, 26, 44, 113, 463, 647, 463, 113, 44, 76, 235, 1493, 2945, 2945, 1493, 235, 76, 130, 521, 5011, 14217, 22049, 14217, 5011, 521, 130, 223, 1107, 16659, 65627, 147672, 147672, 65627, 16659, 1107, 223
Offset: 1
Examples
Array begins: ==================================================================== m\n| 1 2 3 4 5 6 7 8 ---|---------------------------------------------------------------- 1 | 2 3 5 9 15 26 44 76... 2 | 3 5 11 25 51 113 235 521... 3 | 5 11 43 133 463 1493 5011 16659... 4 | 9 25 133 647 2945 14217 65627 322163... 5 | 15 51 463 2945 22049 147672 1043127 7365740... 6 | 26 113 1493 14217 147672 1455385 14656628 151865727... 7 | 44 235 5011 65627 1043127 14656628 218691097 3287831848... 8 | 76 521 16659 322163 7365740 151865727 3287831848 72877697369... ...
Links
- Andrew Howroyd, Table of n, a(n) for n = 1..153
- Matthew D. Kearse and Peter B. Gibbons, Computational Methods and New Results for Chessboard Problems, CDMTCS Research Reports CDMTCS-133 (2000).
- Eric Weisstein's World of Mathematics, King Graph
- Eric Weisstein's World of Mathematics, Irredundant Set