A207267 Number of nX6 0..1 arrays avoiding 0 0 0 and 0 1 1 horizontally and 0 1 1 and 1 0 1 vertically

18, 324, 1014, 3513, 14184, 45520, 135686, 417772, 1253238, 3651096, 10647801, 30923564, 88853464, 254267485, 725590642, 2060214105, 5827339605, 16437397037, 46220378910, 129590864085, 362487844504, 1011664530775, 2817477642474

Offset

1,1

Comments

Column 6 of A207269

Links

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

Formula

Empirical: a(n) = 9*a(n-1) -35*a(n-2) +114*a(n-3) -399*a(n-4) +1079*a(n-5) -2463*a(n-6) +6127*a(n-7) -13098*a(n-8) +23694*a(n-9) -47818*a(n-10) +85704*a(n-11) -127793*a(n-12) +223478*a(n-13) -347915*a(n-14) +432707*a(n-15) -690997*a(n-16) +957544*a(n-17) -986264*a(n-18) +1521595*a(n-19) -1906256*a(n-20) +1579613*a(n-21) -2522281*a(n-22) +2871789*a(n-23) -1799626*a(n-24) +3258588*a(n-25) -3358495*a(n-26) +1404974*a(n-27) -3326664*a(n-28) +3084036*a(n-29) -636076*a(n-30) +2678402*a(n-31) -2235957*a(n-32) +8150*a(n-33) -1672281*a(n-34) +1278000*a(n-35) +212203*a(n-36) +777969*a(n-37) -564416*a(n-38) -156032*a(n-39) -251160*a(n-40) +184308*a(n-41) +55008*a(n-42) +50616*a(n-43) -41472*a(n-44) -8208*a(n-45) -5184*a(n-46) +5184*a(n-47) for n>50

Example

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

Crossrefs

Sequence in context: A207686 A207344 A207486 * A207911 A208423 A207783

Adjacent sequences: A207264 A207265 A207266 * A207268 A207269 A207270

Keyword

nonn

Author

R. H. Hardin Feb 16 2012

Status

approved