A240779 Number of nX4 0..1 arrays with no element equal to fewer vertical neighbors than horizontal neighbors, with new values 0..1 introduced in row major order

1, 6, 46, 305, 2167, 15332, 108509, 767834, 5434887, 38467875, 272273018, 1927138748, 13640213436, 96544878838, 683340799760, 4836658942731, 34233678967243, 242304613789940, 1715022389014131, 12138860042126682

Offset

1,2

Comments

Column 4 of A240783

Links

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

Formula

Empirical: a(n) = 7*a(n-1) +2*a(n-2) -7*a(n-3) -25*a(n-4) -6*a(n-5) +150*a(n-6) +12*a(n-7) -456*a(n-8) -134*a(n-9) +408*a(n-10) +116*a(n-11) -171*a(n-12) +73*a(n-13) +388*a(n-14) +87*a(n-15) -127*a(n-16) -168*a(n-17) -62*a(n-18) -12*a(n-19) +16*a(n-20) +8*a(n-21) +2*a(n-22)

Example

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

Crossrefs

Sequence in context: A079910 A103768 A325947 * A073507 A155598 A190005

Adjacent sequences: A240776 A240777 A240778 * A240780 A240781 A240782

Keyword

nonn

Author

R. H. Hardin, Apr 12 2014

Status

approved