A211913 Number of lower triangular n X n arrays colored with integers 0 upwards introduced in row major order, with no element equal to any horizontal, vertical, diagonal or antidiagonal neighbor, and containing the value n(n+1)/2-4.
0, 0, 10, 802, 27963, 394117, 3243531, 18826250, 85484512, 323341343, 1061434357, 3110902786, 8308425940
Offset: 1
Keywords
Examples
Some solutions for n=4 ..0........0........0........0........0........0........0........0 ..1.2......1.2......1.2......1.2......1.2......1.2......1.2......1.2 ..0.3.4....3.4.5....3.0.4....3.4.0....3.4.5....0.3.4....0.3.4....3.4.5 ..5.6.0.5..0.1.6.7..4.5.6.0..5.6.7.6..2.1.6.3..5.2.6.7..4.5.6.1..1.6.2.1
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