A301821 Number of nX6 0..1 arrays with every element equal to 1 or 2 horizontally or antidiagonally adjacent elements, with upper left element zero.

5, 50, 278, 1351, 6501, 31061, 147954, 705180, 3364845, 16066957, 76746541, 366661633, 1751917453, 8371075480, 39999735173, 191133225006, 913306286525, 4364124497569, 20853452368747, 99645765475503, 476145569567504

Offset

1,1

Comments

Column 6 of A301823.

Links

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

Formula

Empirical: a(n) = 17*a(n-1) -130*a(n-2) +609*a(n-3) -1982*a(n-4) +4783*a(n-5) -8877*a(n-6) +12928*a(n-7) -14910*a(n-8) +13627*a(n-9) -9800*a(n-10) +5461*a(n-11) -2298*a(n-12) +701*a(n-13) -145*a(n-14) +18*a(n-15) -a(n-16) for n>17

Example

Some solutions for n=5
..0..0..1..1..0..0. .0..0..0..1..0..0. .0..0..0..1..0..0. .0..0..0..0..0..0
..0..0..1..0..1..0. .1..1..1..0..1..0. .1..1..1..0..1..1. .1..1..1..1..0..1
..0..1..0..1..0..1. .0..0..0..1..0..1. .0..0..1..1..0..0. .0..0..1..0..1..0
..1..0..1..0..1..1. .1..1..0..0..1..1. .0..0..0..0..1..1. .0..0..1..1..0..0
..0..1..0..0..0..0. .1..1..1..0..0..0. .1..1..1..1..0..0. .0..0..0..1..1..1

Crossrefs

Cf. A301823.

Sequence in context: A274064 A302695 A064054 * A301997 A227883 A227261

Adjacent sequences: A301818 A301819 A301820 * A301822 A301823 A301824

Keyword

nonn

Author

R. H. Hardin, Mar 27 2018

Status

approved