A207348 Number of 4Xn 0..1 arrays avoiding 0 0 0 and 0 1 1 horizontally and 0 0 0 and 1 1 1 vertically

10, 100, 292, 828, 2190, 5290, 12292, 27978, 62574, 136978, 298386, 642668, 1375596, 2932342, 6217164, 13153676, 27743768, 58404696, 122773834, 257696786, 540439948, 1132381262, 2371176338, 4962720854, 10382009670, 21712572508

Offset

1,1

Comments

Row 4 of A207346

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +3*a(n-2) +a(n-3) -16*a(n-4) -5*a(n-5) -2*a(n-6) +38*a(n-7) +8*a(n-8) +26*a(n-9) -59*a(n-10) +12*a(n-11) -61*a(n-12) +55*a(n-13) -57*a(n-14) +59*a(n-15) -62*a(n-16) +61*a(n-17) -41*a(n-18) +48*a(n-19) -31*a(n-20) +19*a(n-21) -20*a(n-22) +7*a(n-23) -5*a(n-24) +4*a(n-25) +a(n-27) for n>28

Example

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

Crossrefs

Sequence in context: A207456 A208836 A208684 * A207770 A207897 A207657

Adjacent sequences: A207345 A207346 A207347 * A207349 A207350 A207351

Keyword

nonn

Author

R. H. Hardin Feb 17 2012

Status

approved