A224151 Number of 7Xn 0..1 arrays with rows and antidiagonals unimodal and columns nondecreasing.
8, 64, 357, 1536, 5471, 16885, 46586, 117510, 275557, 608423, 1277544, 2571226, 4991541, 9394324, 17211567, 30799955, 53979914, 92858530, 157069847, 261620888, 429605663, 696147855, 1114062432, 1761895136, 2755216271, 4262322913
Offset: 1
Keywords
Examples
Some solutions for n=3 ..0..0..0....0..0..0....0..0..0....1..1..0....0..0..0....1..1..1....0..1..0 ..0..1..0....0..0..0....0..0..0....1..1..1....0..1..0....1..1..1....0..1..0 ..0..1..0....0..1..0....0..0..0....1..1..1....0..1..0....1..1..1....0..1..1 ..0..1..0....0..1..1....0..0..0....1..1..1....0..1..0....1..1..1....0..1..1 ..0..1..1....0..1..1....0..1..1....1..1..1....1..1..0....1..1..1....1..1..1 ..0..1..1....0..1..1....0..1..1....1..1..1....1..1..0....1..1..1....1..1..1 ..1..1..1....1..1..1....0..1..1....1..1..1....1..1..1....1..1..1....1..1..1
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Formula
Empirical: a(n) = (1/87178291200)*n^14 + (1/4151347200)*n^13 + (1/136857600)*n^12 + (19/106444800)*n^11 + (53/12441600)*n^10 + (121/1382400)*n^9 + (1007857/609638400)*n^8 + (427321/29030400)*n^7 + (5519/62208)*n^6 + (217709/604800)*n^5 + (8736011/8553600)*n^4 + (1790117/950400)*n^3 + (90367957/37837800)*n^2 + (49717/40040)*n + 1
Comments