A201349 Number of nX4 0..1 arrays with rows and columns lexicographically nondecreasing and every element equal to at least one horizontal or vertical neighbor

3, 14, 47, 191, 752, 2732, 9111, 28011, 79918, 213153, 535318, 1274359, 2892516, 6291669, 13172108, 26642251, 52229342, 99517435, 184747946, 334871408, 593751872, 1031516926, 1758440929, 2945277335, 4852655894, 7873078897

Offset

1,1

Comments

Column 4 of A201353

Links

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

Formula

Empirical: a(n) = (1/1307674368000)*n^15 - (1/87178291200)*n^14 + (19/7472424960)*n^13 - (61/958003200)*n^12 + (48277/14370048000)*n^11 - (293/3483648)*n^10 + (787333/365783040)*n^9 - (24368131/609638400)*n^8 + (200509627/326592000)*n^7 - (316559651/43545600)*n^6 + (9499836221/143700480)*n^5 - (53265620347/119750400)*n^4 + (19358243050561/9081072000)*n^3 - (1030835612797/151351200)*n^2 + (36972827/2860)*n - 10961 for n>4

Example

Some solutions for n=9
..0..0..0..1....0..0..0..1....0..0..0..1....0..0..1..1....0..0..0..0
..0..0..0..1....0..0..0..1....0..0..0..1....0..0..1..1....0..0..0..0
..0..1..1..1....0..0..1..1....0..0..0..1....0..1..0..1....0..0..0..0
..0..1..1..1....0..1..1..1....0..1..1..1....0..1..0..1....0..0..1..1
..1..0..0..1....1..0..0..1....1..0..0..0....1..0..0..0....0..0..1..1
..1..0..1..0....1..1..0..1....1..0..1..0....1..0..0..1....1..1..0..1
..1..0..1..0....1..1..0..1....1..0..1..0....1..0..0..1....1..1..0..1
..1..0..1..1....1..1..1..1....1..1..0..1....1..0..1..1....1..1..0..1
..1..1..1..1....1..1..1..1....1..1..0..1....1..1..1..1....1..1..1..1

Crossrefs

Sequence in context: A202144 A287426 A246149 * A006900 A212505 A024453

Adjacent sequences: A201346 A201347 A201348 * A201350 A201351 A201352

Keyword

nonn

Author

R. H. Hardin Nov 30 2011

Status

approved