A224413 Number of 6Xn 0..1 arrays with rows unimodal and antidiagonals nondecreasing

64, 972, 4636, 13440, 31710, 68282, 139638, 275766, 530583, 999049, 1844709, 3342831, 5946316, 10384152, 17805490, 29986574, 49622914, 80735424, 129226948, 203634878, 316136662, 483878162, 730710330, 1089437826, 1604704333

Offset

1,1

Comments

Row 6 of A224409

Links

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

Formula

Empirical: a(n) = (1/479001600)*n^12 + (1/7257600)*n^11 + (199/43545600)*n^10 + (1/10752)*n^9 + (19951/14515200)*n^8 + (5143/345600)*n^7 + (6148357/43545600)*n^6 + (3015961/1451520)*n^5 + (128983289/10886400)*n^4 + (40193333/604800)*n^3 + (444089893/1663200)*n^2 - (4351/20)*n - 222 for n>4

Example

Some solutions for n=3
..1..1..0....0..1..1....1..1..1....1..0..0....1..1..0....1..1..0....0..0..0
..1..0..0....1..1..1....1..1..0....1..0..0....1..0..0....1..0..0....1..0..0
..0..1..0....1..1..1....1..1..1....0..0..0....0..0..0....1..0..0....0..1..1
..1..0..0....1..1..0....1..1..1....0..0..0....1..0..0....1..0..0....1..1..0
..0..0..1....1..0..0....1..1..0....1..1..0....1..1..1....1..1..0....1..0..0
..1..1..0....0..0..0....1..1..0....1..1..1....1..1..1....1..0..0....0..0..0

Crossrefs

Sequence in context: A000818 A220678 A224162 * A016959 A224392 A224025

Adjacent sequences: A224410 A224411 A224412 * A224414 A224415 A224416

Keyword

nonn

Author

R. H. Hardin Apr 05 2013

Status

approved