A207520 Number of 4Xn 0..1 arrays avoiding 0 0 1 and 0 1 0 horizontally and 0 1 0 and 1 0 1 vertically

10, 100, 358, 1307, 5458, 19909, 68807, 243954, 851870, 2913994, 9973355, 34091714, 115887871, 393267367, 1334118596, 4519810862, 15299142694, 51772884227, 175141804206, 592296849671, 2002747670245, 6771221110994, 22890878459054

Offset

1,1

Comments

Row 4 of A207519

Links

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

Formula

Empirical: a(n) = 6*a(n-1) -12*a(n-2) +39*a(n-3) -140*a(n-4) +171*a(n-5) -344*a(n-6) +1128*a(n-7) -630*a(n-8) +1074*a(n-9) -5032*a(n-10) -196*a(n-11) -1552*a(n-12) +16522*a(n-13) +7292*a(n-14) +1958*a(n-15) -40098*a(n-16) -26944*a(n-17) -3424*a(n-18) +68042*a(n-19) +53864*a(n-20) +7280*a(n-21) -81638*a(n-22) -65348*a(n-23) -9198*a(n-24) +67390*a(n-25) +50740*a(n-26) +5022*a(n-27) -37983*a(n-28) -23800*a(n-29) -594*a(n-30) +14633*a(n-31) +6308*a(n-32) -1205*a(n-33) -3792*a(n-34) -684*a(n-35) +688*a(n-36) +730*a(n-37) -34*a(n-38) -170*a(n-39) -100*a(n-40) +8*a(n-41) +16*a(n-42) +8*a(n-43)

Example

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

Crossrefs

Sequence in context: A207394 A207941 A207468 * A207919 A208699 A207255

Adjacent sequences: A207517 A207518 A207519 * A207521 A207522 A207523

Keyword

nonn

Author

R. H. Hardin Feb 18 2012

Status

approved