A207468 Number of 4Xn 0..1 arrays avoiding 0 0 0 and 0 1 1 horizontally and 0 1 0 and 1 0 1 vertically

10, 100, 358, 1307, 4219, 11760, 33393, 88198, 229458, 590832, 1486909, 3739145, 9312304, 23088739, 57148946, 140903738, 347166896, 854103343, 2099195971, 5157634036, 12663610465, 31086972482, 76294760274, 187208257122

Offset

1,1

Comments

Row 4 of A207467

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +6*a(n-2) -2*a(n-3) -34*a(n-4) -4*a(n-5) +52*a(n-6) +62*a(n-7) -38*a(n-8) -7*a(n-9) -98*a(n-10) -124*a(n-11) -15*a(n-12) +265*a(n-13) +141*a(n-14) +30*a(n-15) -51*a(n-16) -198*a(n-17) -224*a(n-18) -27*a(n-19) +173*a(n-20) +99*a(n-21) +110*a(n-22) -a(n-23) -38*a(n-24) -84*a(n-25) -9*a(n-26) -17*a(n-27) +12*a(n-28) +8*a(n-29) +13*a(n-30) +2*a(n-32) -a(n-33) -a(n-34) -a(n-35)

Example

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

Crossrefs

Sequence in context: A207114 A207394 A207941 * A207520 A207919 A208699

Adjacent sequences: A207465 A207466 A207467 * A207469 A207470 A207471

Keyword

nonn

Author

R. H. Hardin Feb 18 2012

Status

approved