A224414 Number of 7Xn 0..1 arrays with rows unimodal and antidiagonals nondecreasing.
128, 2916, 16684, 52700, 129402, 284254, 590254, 1183226, 2313915, 4440909, 8390988, 15630228, 28711640, 51997668, 92801492, 163153936, 282488024, 481647192, 808773552, 1337828696, 2180752418, 3504587582, 5555307682
Offset: 1
Keywords
Examples
Some solutions for n=3 ..0..0..1....1..1..0....0..0..0....0..0..0....0..1..0....1..0..0....0..1..0 ..0..1..1....1..1..0....1..1..0....1..0..0....1..1..0....0..0..0....1..1..0 ..1..1..0....1..0..0....1..0..0....0..0..0....1..0..0....0..0..0....1..0..0 ..1..0..0....0..0..1....0..0..0....1..0..0....0..1..0....1..1..0....0..0..1 ..1..0..0....0..1..0....0..0..0....1..0..0....1..0..0....1..1..0....1..1..0 ..0..0..0....1..0..0....0..0..0....0..0..0....1..0..0....1..0..0....1..1..0 ..0..1..0....0..0..1....0..1..1....0..1..1....0..1..1....0..1..0....1..1..1
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Formula
Empirical: a(n) = (1/87178291200)*n^14 + (1/958003200)*n^13 + (1/21288960)*n^12 + (23/17418240)*n^11 + (331/12441600)*n^10 + (11671/29030400)*n^9 + (612743/121927680)*n^8 + (25375/497664)*n^7 + (15815113/14515200)*n^6 + (109956869/21772800)*n^5 + (221348047/3421440)*n^4 + (154662289/665280)*n^3 + (81821289727/75675600)*n^2 - (157721/140)*n - 1044 for n>5
Comments