A225982 T(n,k)=Number of nXk binary arrays whose sum with another nXk binary array containing no more than two 1s has rows and columns in lexicographically nondecreasing order.

2, 4, 4, 8, 15, 8, 15, 48, 48, 15, 26, 138, 252, 138, 26, 42, 350, 1178, 1178, 350, 42, 64, 790, 4722, 9113, 4722, 790, 64, 93, 1616, 16361, 61808, 61808, 16361, 1616, 93, 130, 3049, 49811, 361361, 737893, 361361, 49811, 3049, 130, 176, 5384, 135672, 1825607

Offset: 1

Author

R. H. Hardin May 22 2013

Keywords

• nonn
• tabl

Comments

Table starts

...2....4......8........15..........26............42.............64

...4...15.....48.......138.........350...........790...........1616

...8...48....252......1178........4722.........16361..........49811

..15..138...1178......9113.......61808........361361........1825607

..26..350...4722.....61808......737893.......7718077.......69784592

..42..790..16361....361361.....7718077.....148890101.....2513743785

..64.1616..49811...1825607....69784592....2513743785....80901937149

..93.3049.135672...8065278...546720823...36836074434..2279339811483

.130.5384.336189..31631401..3748375290..470279869497.56056577764123

.176.9001.768900.111785599.22776885553.5279223820491

Examples

			Some solutions for n=3 k=4
..0..0..1..1....0..0..1..1....0..1..1..0....1..1..1..1....0..0..1..1
..1..1..1..1....1..1..0..0....0..1..1..0....1..1..1..1....0..0..0..1
..1..0..0..1....0..0..0..1....1..0..0..0....1..0..1..0....1..1..1..1
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..127

Crossrefs

Column 1 is A000125

Formula

Empirical: columns k=1..5 are polynomials in n of degree 2^k+1 for n>0,0,1,2,2