A224261 Number of n X 7 0..2 arrays with rows, diagonals and antidiagonals unimodal and columns nondecreasing.

239, 9503, 119367, 850875, 4542734, 20568693, 83124099, 306179180, 1038489172, 3266157979, 9583669559, 26387428383, 68551067596, 168889679757, 396460357949, 890533215416, 1921389717480, 3995624313351, 8033215042947, 15657425192703, 29658055171558, 54715516508103

Offset: 1

Author

R. H. Hardin, Apr 02 2013

Keywords

• nonn

Examples

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

Links

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

Crossrefs

Column 7 of A224262.

Formula

Empirical: a(n) = (118519/21794572800)*n^14 + (2257/124540416)*n^13 + (11489/13305600)*n^12 + (227251/47900160)*n^11 + (39637/777600)*n^10 + (458077/1451520)*n^9 + (169757921/76204800)*n^8 + (6354631/870912)*n^7 + (526598447/7257600)*n^6 + (85059797/2177280)*n^5 + (6141145069/8553600)*n^4 - (2165544719/1995840)*n^3 - (174076430267/75675600)*n^2 - (921446093/36036)*n + 109916 for n>8.

Extensions

Name corrected by Andrew Howroyd, Mar 18 2025