A227254 Number of nX4 binary arrays indicating whether each 2X2 subblock of a larger binary array has lexicographically nondecreasing rows and columns, for some larger (n+1)X5 binary array with rows and columns of the latter in lexicographically nondecreasing order

7, 23, 134, 813, 4578, 22659, 98821, 388681, 1403516, 4714206, 14875044, 44432556, 126415358, 344289685, 901306978, 2275929413, 5559947847, 13174033412, 30343762095, 68072517741, 148997133853, 318682656840, 666983823620

Offset

1,1

Comments

Column 4 of A227256

Links

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

Formula

Empirical: a(n) = (1/1615751046180311040000)*n^23 - (1/17562511371525120000)*n^22 + (47/6386367771463680000)*n^21 - (61/130334036152320000)*n^20 + (137/4607768954880000)*n^19 - (3013/2286562037760000)*n^18 + (8844359/168062309775360000)*n^17 - (312287/190115735040000)*n^16 + (886379059/19772036444160000)*n^15 - (1420704487/1412288317440000)*n^14 + (203799917239/10356780994560000)*n^13 - (12399719441/37936926720000)*n^12 + (1063351164833/224682232320000)*n^11 - (1154985638557243/19772036444160000)*n^10 + (275422039495271/449364464640000)*n^9 - (7500326892522067/1412288317440000)*n^8 + (9240597952126787/250092722880000)*n^7 - (13880538229405699/71455063680000)*n^6 + (137736482787968773/205323037920000)*n^5 - (360812024910147697/568586874240000)*n^4 - (1806440435059302017/225855341712000)*n^3 + (164721791470756099/3226504881600)*n^2 - (12692795286877/89237148)*n + 166461 for n>8

Example

Some solutions for n=4
..1..1..1..0....1..1..1..1....1..1..1..1....1..0..0..1....1..1..1..1
..1..1..0..1....1..0..1..1....1..0..0..0....0..1..1..1....1..0..0..1
..1..1..1..0....0..1..1..0....0..1..1..0....0..1..0..0....0..1..1..1
..1..0..0..0....1..1..1..0....1..1..1..1....1..1..0..1....0..1..0..0

Crossrefs

Sequence in context: A064639 A064638 A082021 * A080082 A158954 A056205

Adjacent sequences: A227251 A227252 A227253 * A227255 A227256 A227257

Keyword

nonn

Author

R. H. Hardin Jul 04 2013

Status

approved