A235551 Number of (n+1)X(3+1) 0..1 arrays with the sum of each 2X2 subblock two extreme terms minus its two median terms lexicographically nondecreasing rowwise and columnwise

120, 814, 5567, 33851, 184281, 892122, 3925717, 15834473, 59506551, 209811804, 701617754, 2235893345, 6840089137, 20153696074, 57486754527, 159114503083, 428959896263, 1128320167213, 2903976632760, 7322640491124, 18130800682746

Offset

1,1

Comments

Column 3 of A235555

Links

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

Formula

Empirical: a(n) = 4*a(n-1) +35*a(n-2) -158*a(n-3) -566*a(n-4) +2984*a(n-5) +5518*a(n-6) -35860*a(n-7) -34899*a(n-8) +307860*a(n-9) +134985*a(n-10) -2009442*a(n-11) -146036*a(n-12) +10361384*a(n-13) -2055944*a(n-14) -43291072*a(n-15) +17856377*a(n-16) +149141740*a(n-17) -88146091*a(n-18) -428837090*a(n-19) +320702778*a(n-20) +1037666520*a(n-21) -926474634*a(n-22) -2123839620*a(n-23) +2196630507*a(n-24) +3685625340*a(n-25) -4350171921*a(n-26) -5420700030*a(n-27) +7267723728*a(n-28) +6732949080*a(n-29) -10298203356*a(n-30) -7007379432*a(n-31) +12402868752*a(n-32) +6021828864*a(n-33) -12690037008*a(n-34) -4154733792*a(n-35) +10997624704*a(n-36) +2163244160*a(n-37) -8028312512*a(n-38) -698220160*a(n-39) +4894723328*a(n-40) -31167488*a(n-41) -2461727488*a(n-42) +213300736*a(n-43) +1003462656*a(n-44) -156899328*a(n-45) -323171328*a(n-46) +70256640*a(n-47) +79130624*a(n-48) -21463040*a(n-49) -13840384*a(n-50) +4415488*a(n-51) +1540096*a(n-52) -557056*a(n-53) -81920*a(n-54) +32768*a(n-55)

Example

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

Crossrefs

Sequence in context: A052627 A251264 A206025 * A300664 A029573 A211471

Adjacent sequences: A235548 A235549 A235550 * A235552 A235553 A235554

Keyword

nonn

Author

R. H. Hardin, Jan 12 2014

Status

approved