A253222 Number of n X 7 nonnegative integer arrays with upper left 0 and lower right its king-move distance away minus 2 and every value within 2 of its king move distance from the upper left and every value increasing by 0 or 1 with every step right, diagonally se or down.

15, 81, 504, 3140, 16028, 47698, 47698, 649712, 2913793, 7415837, 14420585, 24015795, 36221327, 51039931, 68471783, 88516883, 111175231, 136446827, 164331671, 194829763, 227941103, 263665691, 302003527, 342954611, 386518943

Offset: 1

Author

R. H. Hardin, Dec 29 2014

Keywords

• nonn

Comments

Column 7 of A253223.

Examples

			Some solutions for n=4
..0..1..2..2..3..3..4....0..0..1..2..3..3..4....0..0..1..2..3..3..4
..1..1..2..2..3..4..4....0..1..1..2..3..3..4....0..1..1..2..3..3..4
..2..2..2..3..3..4..4....1..1..1..2..3..3..4....1..1..2..2..3..4..4
..2..2..2..3..3..4..4....1..1..1..2..3..3..4....2..2..2..2..3..4..4
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..210

Crossrefs

Cf. A253223.

Formula

Empirical: a(n) = 1306624*n^2 - 20460244*n + 81385043 for n>12.