A207444 Number of 4Xn 0..1 arrays avoiding 0 0 1 and 0 1 0 horizontally and 0 0 1 and 1 0 0 vertically

9, 81, 333, 1360, 6092, 25689, 105690, 439332, 1821924, 7521414, 31063445, 128325745, 529821580, 2187257369, 9030334421, 37280871533, 153905038835, 635365800266, 2622977336044, 10828351058245, 44702329730212

Offset

1,1

Comments

Row 4 of A207442

Links

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

Formula

Empirical: a(n) = 5*a(n-1) -4*a(n-2) +21*a(n-3) -78*a(n-4) -31*a(n-5) -41*a(n-6) +475*a(n-7) +568*a(n-8) -94*a(n-9) -2370*a(n-10) -2473*a(n-11) +670*a(n-12) +6654*a(n-13) +6859*a(n-14) -1652*a(n-15) -11383*a(n-16) -11186*a(n-17) +818*a(n-18) +11923*a(n-19) +11553*a(n-20) +1019*a(n-21) -6760*a(n-22) -7392*a(n-23) -1944*a(n-24) +1915*a(n-25) +2670*a(n-26) +1090*a(n-27) -64*a(n-28) -529*a(n-29) -259*a(n-30) -53*a(n-31) +46*a(n-32) +24*a(n-33) +8*a(n-34) -4*a(n-35)

Example

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

Crossrefs

Sequence in context: A207501 A207438 A208138 * A207428 A208370 A207422

Adjacent sequences: A207441 A207442 A207443 * A207445 A207446 A207447

Keyword

nonn

Author

R. H. Hardin Feb 17 2012

Status

approved