A224163 Number of 7Xn 0..1 arrays with diagonals and rows unimodal and antidiagonals nondecreasing.
128, 2916, 9681, 18408, 32910, 60214, 114537, 222841, 437497, 857104, 1662992, 3177801, 5958392, 10937977, 19639113, 34486391, 59258268, 99731248, 164588012, 266685480, 424810970, 666096886, 1029319580, 1569379741, 2363354232
Offset: 1
Keywords
Examples
Some solutions for n=3 ..0..0..0....1..0..0....0..1..0....0..0..0....0..0..1....0..0..0....1..1..0 ..0..0..0....1..0..0....1..0..0....0..1..0....1..1..1....0..0..1....1..0..0 ..0..0..0....0..0..0....0..0..0....1..0..0....1..1..1....1..1..0....1..1..0 ..1..0..0....0..0..0....1..0..0....1..0..0....1..1..0....1..0..0....1..0..0 ..0..0..0....0..0..1....1..0..0....0..0..0....1..0..0....0..1..0....0..1..0 ..1..0..0....1..1..0....1..0..0....1..0..0....1..0..0....1..1..0....1..0..0 ..0..0..0....1..1..1....1..1..0....0..0..0....1..1..0....1..0..0....1..0..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Formula
Empirical: a(n) = (1/87178291200)*n^14 - (1/1779148800)*n^13 + (1/35481600)*n^12 - (599/958003200)*n^11 + (2503/87091200)*n^10 - (15289/29030400)*n^9 + (14386957/609638400)*n^8 - (43214887/87091200)*n^7 + (53001143/7257600)*n^6 - (371883179/5443200)*n^5 + (31780522507/59875200)*n^4 - (22988847851/6652800)*n^3 + (639379939651/30270240)*n^2 - (888679471/10010)*n + 189847 for n>10
Comments