A268969 Number of n X 6 0..2 arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two not more than once.

336, 11664, 339480, 9093528, 231730344, 5712070032, 137497776840, 3251386055664, 75828095546544, 1748970953035272, 39976056137974824, 906854671261865016, 20440902679961179824, 458229741557275128024

Offset

1,1

Links

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

Formula

Empirical: a(n) = 50*a(n-1) - 805*a(n-2) + 4662*a(n-3) - 12150*a(n-4) + 14580*a(n- 5) -6561*a(n-6).

Empirical g.f.: 24*x*(14 - 214*x + 1115*x^2 - 2391*x^3 + 1674*x^4 + 243*x^5) / (1 - 25*x + 90*x^2 - 81*x^3)^2. - Colin Barker, Jan 17 2019

Example

Some solutions for n=2:
..1..0..0..0..1..2. .1..2..2..0..1..2. .0..0..1..2..2..2. .1..0..1..0..0..0
..0..1..0..0..1..1. .1..2..1..2..2..2. .0..1..2..2..2..2. .1..0..0..0..0..0

Crossrefs

Column 6 of A268971.

Sequence in context: A229697 A268626 A258418 * A056933 A289346 A008693

Adjacent sequences: A268966 A268967 A268968 * A268970 A268971 A268972

Keyword

nonn

Author

R. H. Hardin, Feb 16 2016

Status

approved