A207878 Number of nX7 0..1 arrays avoiding 0 0 0 and 1 0 1 horizontally and 0 1 0 and 1 1 1 vertically

28, 784, 1488, 4200, 8892, 24952, 51696, 136490, 313524, 741944, 1781472, 4256398, 10168008, 23945116, 57760744, 138028240, 325742600, 781955124, 1868173840, 4441180174, 10581963516, 25315989248, 60356380176, 143569382950

Offset

1,1

Comments

Column 7 of A207879

Links

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

Formula

Empirical: a(n) = 2*a(n-2) +16*a(n-3) +9*a(n-4) -30*a(n-5) -124*a(n-6) -40*a(n-7) +210*a(n-8) +544*a(n-9) +116*a(n-10) -950*a(n-11) -1335*a(n-12) -420*a(n-13) +2586*a(n-14) +2672*a(n-15) +1600*a(n-16) -5088*a(n-17) -5011*a(n-18) -2288*a(n-19) +4642*a(n-20) +9096*a(n-21) +3040*a(n-22) -912*a(n-23) -10304*a(n-24) -6144*a(n-25) -436*a(n-26) +4768*a(n-27) +6648*a(n-28) +1728*a(n-29) -528*a(n-30) -3456*a(n-31) -2016*a(n-32) +1152*a(n-34) for n>40

Example

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

Crossrefs

Sequence in context: A223495 A209228 A208505 * A207681 A207894 A207884

Adjacent sequences: A207875 A207876 A207877 * A207879 A207880 A207881

Keyword

nonn

Author

R. H. Hardin Feb 21 2012

Status

approved