A235550 Number of (n+1)X(2+1) 0..1 arrays with the sum of each 2X2 subblock two extreme terms minus its two median terms lexicographically nondecreasing rowwise and columnwise

46, 202, 814, 2878, 9320, 27731, 77606, 205571, 522118, 1277701, 3035682, 7026779, 15922886, 35411253, 77537074, 167468443, 357585774, 755895685, 1584418882, 3296648763, 6816697174, 14019547045, 28702737170, 58535302827, 118984571742

Offset

1,1

Comments

Column 2 of A235555

Links

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

Formula

Empirical: a(n) = 4*a(n-1) +9*a(n-2) -54*a(n-3) -15*a(n-4) +312*a(n-5) -133*a(n-6) -998*a(n-7) +840*a(n-8) +1896*a(n-9) -2268*a(n-10) -2088*a(n-11) +3472*a(n-12) +1088*a(n-13) -3120*a(n-14) +96*a(n-15) +1536*a(n-16) -384*a(n-17) -320*a(n-18) +128*a(n-19)

Example

Some solutions for n=5
..1..0..1....0..1..0....1..1..1....1..0..1....0..1..0....1..0..0....1..0..1
..0..1..0....1..1..0....0..1..0....1..1..1....0..1..0....1..1..1....1..1..1
..1..0..1....0..1..0....1..1..0....0..1..1....1..0..0....1..0..0....0..0..0
..1..0..0....1..0..1....1..0..1....0..1..0....1..0..1....0..1..0....0..0..0
..0..1..0....0..1..0....0..1..1....1..0..1....0..0..0....0..0..1....0..0..1
..1..0..0....0..0..1....0..0..0....0..1..0....0..1..0....1..0..0....1..0..1

Crossrefs

Sequence in context: A192850 A211334 A160334 * A083358 A254229 A234161

Adjacent sequences: A235547 A235548 A235549 * A235551 A235552 A235553

Keyword

nonn

Author

R. H. Hardin, Jan 12 2014

Status

approved