A226870 T(n,k)=Number of nXk (-1,0,1) arrays of determinants of 2X2 subblocks of some (n+1)X(k+1) binary array with rows and columns of the latter in lexicographically nondecreasing order

2, 4, 4, 7, 13, 7, 11, 37, 37, 11, 16, 91, 187, 91, 16, 22, 199, 792, 792, 199, 22, 29, 397, 2866, 6195, 2866, 397, 29, 37, 736, 9136, 41222, 41222, 9136, 736, 37, 46, 1285, 26267, 235528, 523701, 235528, 26267, 1285, 46, 56, 2134, 69311, 1179663, 5692900

Offset

1,1

Comments

Table starts

..2....4......7.......11.........16...........22............29............37

..4...13.....37.......91........199..........397...........736..........1285

..7...37....187......792.......2866.........9136.........26267.........69311

.11...91....792.....6195......41222.......235528.......1179663.......5279390

.16..199...2866....41222.....523701......5692900......53537470.....442630782

.22..397...9136...235528....5692900....119835087....2182420206...34737998303

.29..736..26267..1179663...53537470...2182420206...77611438870.2412616653873

.37.1285..69311..5279390..442630782..34737998303.2412616653873

.46.2134.170084.21450391.3265819433.489248332852

Links

R. H. Hardin, Table of n, a(n) for n = 1..112

Formula

Empirical: column k is a polynomial in n of degree 3*2^(k-1)-1 for k in 1..5 and n>0,0,1,5,13

Example

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

Crossrefs

Column 1 is A000124

Sequence in context: A297085 A224158 A224409 * A227751 A268995 A205744

Adjacent sequences: A226867 A226868 A226869 * A226871 A226872 A226873

Keyword

nonn,tabl

Author

R. H. Hardin Jun 20 2013

Status

approved