A207273 Number of 6Xn 0..1 arrays avoiding 0 0 0 and 0 1 1 horizontally and 0 1 1 and 1 0 1 vertically

21, 441, 1087, 5132, 18055, 45520, 140295, 349415, 877101, 2164569, 5025447, 11757247, 26570861, 59370361, 131185317, 285043185, 615447774, 1313196034, 2780365566, 5844983027, 12192162619, 25292923072, 52147005064, 106956186914

Offset

1,1

Comments

Row 6 of A207269

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +10*a(n-2) +3*a(n-3) -91*a(n-4) -114*a(n-5) +279*a(n-6) +1060*a(n-7) +127*a(n-8) -3605*a(n-9) -6043*a(n-10) +3868*a(n-11) +21907*a(n-12) +21779*a(n-13) -28295*a(n-14) -86016*a(n-15) -61000*a(n-16) +105502*a(n-17) +251602*a(n-18) +159014*a(n-19) -258940*a(n-20) -589991*a(n-21) -403075*a(n-22) +444651*a(n-23) +1134524*a(n-24) +917203*a(n-25) -500154*a(n-26) -1770406*a(n-27) -1742187*a(n-28) +194051*a(n-29) +2177951*a(n-30) +2674848*a(n-31) +564317*a(n-32) -1999418*a(n-33) -3269662*a(n-34) -1515627*a(n-35) +1171675*a(n-36) +3131481*a(n-37) +2150458*a(n-38) -76185*a(n-39) -2282504*a(n-40) -2121528*a(n-41) -729515*a(n-42) +1182231*a(n-43) +1536355*a(n-44) +956874*a(n-45) -338821*a(n-46) -810406*a(n-47) -741228*a(n-48) -55941*a(n-49) +288519*a(n-50) +404337*a(n-51) +126196*a(n-52) -47575*a(n-53) -160958*a(n-54) -77482*a(n-55) -14952*a(n-56) +46223*a(n-57) +29307*a(n-58) +14005*a(n-59) -9038*a(n-60) -7444*a(n-61) -5393*a(n-62) +1011*a(n-63) +1250*a(n-64) +1312*a(n-65) -15*a(n-66) -127*a(n-67) -211*a(n-68) -11*a(n-69) +6*a(n-70) +21*a(n-71) +a(n-72) -a(n-74) for n>75

Example

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

Crossrefs

Sequence in context: A171326 A092499 A207776 * A207766 A207733 A208692

Adjacent sequences: A207270 A207271 A207272 * A207274 A207275 A207276

Keyword

nonn

Author

R. H. Hardin Feb 16 2012

Status

approved