A301822 Number of nX7 0..1 arrays with every element equal to 1 or 2 horizontally or antidiagonally adjacent elements, with upper left element zero.

8, 128, 968, 6653, 47363, 333335, 2341241, 16471479, 115975709, 816674776, 5750906471, 40498618037, 285206498639, 2008567595662, 14145438133381, 99620184969372, 701582362197999, 4940946394826023, 34796990566402966

Offset

1,1

Comments

Column 7 of A301823.

Links

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

Formula

Empirical: a(n) = 30*a(n-1) -418*a(n-2) +3654*a(n-3) -22669*a(n-4) +106606*a(n-5) -395403*a(n-6) +1186422*a(n-7) -2928707*a(n-8) +6014938*a(n-9) -10354804*a(n-10) +15013356*a(n-11) -18384098*a(n-12) +19034892*a(n-13) -16660310*a(n-14) +12301356*a(n-15) -7624215*a(n-16) +3923202*a(n-17) -1635354*a(n-18) +519982*a(n-19) -103769*a(n-20) -2026*a(n-21) +11017*a(n-22) -4610*a(n-23) +1059*a(n-24) -138*a(n-25) +8*a(n-26) for n>28

Example

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

Crossrefs

Cf. A301823.

Sequence in context: A302268 A302967 A302071 * A302810 A061549 A303471

Adjacent sequences: A301819 A301820 A301821 * A301823 A301824 A301825

Keyword

nonn

Author

R. H. Hardin, Mar 27 2018

Status

approved