A223842 Number of 6 X n 0..1 arrays with rows 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

Offset

1,1

Comments

Row 6 of A223838.

Links

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

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.

Example

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

Crossrefs

Cf. A223838.

Sequence in context: A181219 A141783 A181479 * A212693 A223615 A188768

Adjacent sequences: A223839 A223840 A223841 * A223843 A223844 A223845

Keyword

nonn

Author

R. H. Hardin Mar 27 2013

Status

approved