A206937 Number of 4Xn 0..1 arrays avoiding 0 0 0 horizontally and 0 1 1 vertically

12, 144, 811, 6837, 55088, 410000, 3227589, 25102409, 193788386, 1507133620, 11693492167, 90677582325, 703826743120, 5460755855460, 42367807894797, 328752895890725, 2550786798536934, 19791666524580132, 153566455887582047

Offset

1,1

Comments

Row 4 of A206936

Links

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

Formula

Empirical: a(n) = -a(n-1) +16*a(n-2) +284*a(n-3) +847*a(n-4) +1819*a(n-5) -6372*a(n-6) -18220*a(n-7) -55347*a(n-8) +68879*a(n-9) +139274*a(n-10) +648892*a(n-11) -473781*a(n-12) -401797*a(n-13) -3963592*a(n-14) +2110836*a(n-15) -80057*a(n-16) +13663197*a(n-17) -5668754*a(n-18) +2666692*a(n-19) -27046299*a(n-20) +8341017*a(n-21) -4950884*a(n-22) +30801116*a(n-23) -6296865*a(n-24) +3755693*a(n-25) -20614026*a(n-26) +2290372*a(n-27) -1349783*a(n-28) +8200897*a(n-29) -284960*a(n-30) +233228*a(n-31) -1895282*a(n-32) -35800*a(n-33) -22846*a(n-34) +234592*a(n-35) +9816*a(n-36) +2512*a(n-37) -12944*a(n-38) -240*a(n-39) -64*a(n-40) +256*a(n-41)

Example

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

Crossrefs

Sequence in context: A208290 A208139 A208145 * A188602 A188690 A278121

Adjacent sequences: A206934 A206935 A206936 * A206938 A206939 A206940

Keyword

nonn

Author

R. H. Hardin Feb 13 2012

Status

approved