A223842 Number of 6 X n 0..1 arrays with rows, diagonals and antidiagonals unimodal and columns nondecreasing.
7, 49, 232, 824, 2388, 5992, 13582, 28642, 57306, 110164, 205131, 371923, 658926, 1143584, 1947904, 3261320, 5374024, 8725020, 13970658, 22081342, 34476575, 53211615, 81232894, 122724138, 183570978, 271978936, 399288201, 581038793, 838351784, 1199706462, 1703209968
Offset: 1
Keywords
Examples
Some solutions for n=3: ..0..1..0....0..0..0....0..0..0....0..0..0....1..1..0....0..0..0....0..0..0 ..0..1..0....1..0..0....0..0..0....0..0..0....1..1..0....0..0..0....0..0..0 ..0..1..0....1..0..0....0..0..1....0..0..0....1..1..0....0..1..0....0..0..0 ..0..1..0....1..1..0....0..1..1....0..0..0....1..1..0....0..1..1....1..0..0 ..0..1..0....1..1..1....1..1..1....0..0..0....1..1..1....1..1..1....1..1..0 ..1..1..0....1..1..1....1..1..1....0..1..1....1..1..1....1..1..1....1..1..1
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Crossrefs
Row 6 of A223838.
Formula
Empirical: a(n) = (1/479001600)*n^12 - (1/15966720)*n^11 + (13/6220800)*n^10 - (1/53760)*n^9 + (6631/14515200)*n^8 + (125/96768)*n^7 - (1017767/43545600)*n^6 + (1429367/1451520)*n^5 - (7479853/1555200)*n^4 + (4300223/120960)*n^3 - (151629803/1663200)*n^2 - (12136/231)*n + 528 for n>6.
Extensions
Name corrected by Andrew Howroyd, Mar 18 2025