A226868 Number of nX4 (-1,0,1) arrays of determinants of 2X2 subblocks of some (n+1)X5 binary array with rows and columns of the latter in lexicographically nondecreasing order

11, 91, 792, 6195, 41222, 235528, 1179663, 5279390, 21450391, 80163310, 278497578, 907289100, 2791617118, 8160858953, 22780131186, 60975863607, 157078679556, 390656580964, 940538345174, 2197356106902, 4992114741415, 11049541664919

Offset

1,1

Comments

Column 4 of A226870

Links

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

Formula

Empirical: a(n) = (1/39895087560007680000)*n^23 - (1/1156379349565440000)*n^22 + (31/236532139683840000)*n^21 - (283/90107481784320000)*n^20 + (9067/45053740892160000)*n^19 - (38231/14227497123840000)*n^18 + (514669/5532915548160000)*n^17 + (94049/976396861440000)*n^16 - (1341139/732297646080000)*n^15 + (551917/1107025920000)*n^14 - (3294587311/767168962560000)*n^13 + (32197879519/708155965440000)*n^12 + (449013326383/976396861440000)*n^11 - (17775513984467/1952793722880000)*n^10 + (307489530723593/2929190584320000)*n^9 - (18254938832597/34871316480000)*n^8 + (218159407677791/296406190080000)*n^7 + (10418027129737729/889218570240000)*n^6 - (1942722234280615327/19711011640320000)*n^5 + (573780866912018197/1231938227520000)*n^4 - (483951429128288267/301140455616000)*n^3 + (4624723720846583/1075501627200)*n^2 - (2316066603161/297457160)*n + 6853 for n>5

Example

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

Crossrefs

Sequence in context: A125374 A245599 A126532 * A199678 A201549 A117611

Adjacent sequences: A226865 A226866 A226867 * A226869 A226870 A226871

Keyword

nonn

Author

R. H. Hardin Jun 20 2013

Status

approved