A235731 Number of (n+1)X(3+1) 0..1 arrays with the sum of each 2X2 subblock maximum and minimum lexicographically nondecreasing columnwise and nonincreasing rowwise

209, 2481, 29130, 337412, 3906424, 45143913, 521746721, 6028565252, 69659874030, 804890692193, 9300241852444, 107460665822569, 1241667704762525, 14346994859722417, 165774069260192855, 1915456124041041749

Offset

1,1

Comments

Column 3 of A235736

Links

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

Formula

Empirical: a(n) = 13*a(n-1) +31*a(n-2) -636*a(n-3) +89*a(n-4) +12041*a(n-5) -11270*a(n-6) -120541*a(n-7) +154024*a(n-8) +740489*a(n-9) -1063058*a(n-10) -3026569*a(n-11) +4525730*a(n-12) +8621311*a(n-13) -12861384*a(n-14) -17576669*a(n-15) +25344090*a(n-16) +26012635*a(n-17) -35238430*a(n-18) -28101627*a(n-19) +34713900*a(n-20) +22128559*a(n-21) -24080258*a(n-22) -12584223*a(n-23) +11581011*a(n-24) +5060172*a(n-25) -3764571*a(n-26) -1380959*a(n-27) +796769*a(n-28) +237764*a(n-29) -104144*a(n-30) -22656*a(n-31) +7728*a(n-32) +896*a(n-33) -256*a(n-34)

Example

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

Crossrefs

Sequence in context: A305455 A305020 A316684 * A235512 A203040 A250951

Adjacent sequences: A235728 A235729 A235730 * A235732 A235733 A235734

Keyword

nonn

Author

R. H. Hardin, Jan 15 2014

Status

approved