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

1,1

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

Links

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

Formula

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

Example

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

Crossrefs

Column 1 is A000125

Sequence in context: A181245 A216950 A240364 * A282528 A297094 A283282

Adjacent sequences: A225979 A225980 A225981 * A225983 A225984 A225985

Keyword

nonn,tabl

Author

R. H. Hardin May 22 2013

Status

approved