A207001 Number of 4Xn 0..1 arrays avoiding 0 1 0 horizontally and 0 1 1 vertically

12, 144, 1020, 6612, 45932, 329734, 2346621, 16555996, 116824836, 825944298, 5841333854, 41296838816, 291917220483, 2063599965447, 14588455360112, 103131522271050, 729070029502689, 5154026289337418, 36435512589728099

Offset

1,1

Comments

Row 4 of A207000

Links

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

Formula

Empirical: a(n) = 12*a(n-1) -66*a(n-2) +302*a(n-3) -765*a(n-4) +1446*a(n-5) -323*a(n-6) -5615*a(n-7) +13155*a(n-8) -14780*a(n-9) -33360*a(n-10) +114407*a(n-11) -55387*a(n-12) -144528*a(n-13) +485368*a(n-14) -387119*a(n-15) -1329517*a(n-16) +1697828*a(n-17) +2024417*a(n-18) -2840081*a(n-19) -1775201*a(n-20) +2598810*a(n-21) +710729*a(n-22) -1248295*a(n-23) +112490*a(n-24) +169231*a(n-25) -221480*a(n-26) +97360*a(n-27) +61312*a(n-28) -26508*a(n-29) +917*a(n-30) -3775*a(n-31) -1940*a(n-32) +564*a(n-33) +66*a(n-34) +376*a(n-35) -3*a(n-36) -41*a(n-37) +9*a(n-38) -8*a(n-39) -a(n-40) +a(n-41)

Example

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

Crossrefs

Sequence in context: A206879 A206996 A188518 * A206781 A188769 A206885

Adjacent sequences: A206998 A206999 A207000 * A207002 A207003 A207004

Keyword

nonn

Author

R. H. Hardin Feb 14 2012

Status

approved