A238249 Number of (n+1)X(2+1) 0..1 arrays with 2X2 subblock sums lexicographically nondecreasing columnwise and rowwise

44, 180, 804, 2818, 9991, 29995, 90225, 241945, 649320, 1605951, 3974215, 9269399, 21628177, 48322967, 107991481, 233776405, 506133563, 1070574873, 2264593031, 4710021487, 9796211590, 20129009598, 41359935334, 84255978136, 171637137305

Offset

1,1

Comments

Column 2 of A238255

Links

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

Formula

Empirical: a(n) = 4*a(n-1) +16*a(n-2) -82*a(n-3) -99*a(n-4) +774*a(n-5) +196*a(n-6) -4456*a(n-7) +1106*a(n-8) +17464*a(n-9) -10080*a(n-10) -49212*a(n-11) +40922*a(n-12) +102532*a(n-13) -108728*a(n-14) -159592*a(n-15) +207747*a(n-16) +184428*a(n-17) -296048*a(n-18) -153442*a(n-19) +318857*a(n-20) +83878*a(n-21) -259308*a(n-22) -19872*a(n-23) +157052*a(n-24) -10232*a(n-25) -68768*a(n-26) +12128*a(n-27) +20592*a(n-28) -5472*a(n-29) -3776*a(n-30) +1280*a(n-31) +320*a(n-32) -128*a(n-33)

Example

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

Crossrefs

Sequence in context: A235407 A006563 A159033 * A189547 A026908 A183246

Adjacent sequences: A238246 A238247 A238248 * A238250 A238251 A238252

Keyword

nonn

Author

R. H. Hardin, Feb 21 2014

Status

approved