A207684 Number of 4Xn 0..1 arrays avoiding 0 0 0 and 1 0 1 horizontally and 0 0 1 and 1 1 1 vertically

9, 81, 166, 436, 964, 2132, 4846, 11301, 25496, 57407, 131250, 299913, 680860, 1542076, 3516426, 8019977, 18194846, 41334779, 94226716, 214384000, 486836482, 1107706812, 2522185912, 5733889814, 13035303238, 29665346161, 67490142684

Offset

1,1

Comments

Row 4 of A207682

Links

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

Formula

Empirical: a(n) = 12*a(n-3) +12*a(n-4) +4*a(n-5) -54*a(n-6) -70*a(n-7) -34*a(n-8) +148*a(n-9) +164*a(n-10) +54*a(n-11) -237*a(n-12) -184*a(n-13) -12*a(n-14) +234*a(n-15) +87*a(n-16) -22*a(n-17) -126*a(n-18) -36*a(n-19) +19*a(n-20) +32*a(n-21) +14*a(n-22) -2*a(n-24) for n>26

Example

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

Crossrefs

Sequence in context: A043180 A207875 A207678 * A207510 A208104 A207725

Adjacent sequences: A207681 A207682 A207683 * A207685 A207686 A207687

Keyword

nonn

Author

R. H. Hardin Feb 19 2012

Status

approved