A318218 Number of nX4 0..1 arrays with every element unequal to 2, 3, 4 or 5 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

0, 2, 18, 174, 1538, 13722, 123415, 1108310, 9952342, 89374736, 802604215, 7207554901, 64725391117, 581247882251, 5219730484108, 46874298003145, 420941238200854, 3780142499106704, 33946489479324642, 304846748037181812

Offset

1,2

Comments

Column 4 of A318222.

Links

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

Formula

Empirical: a(n) = 10*a(n-1) -13*a(n-2) +42*a(n-3) -66*a(n-4) +9*a(n-5) -173*a(n-6) -166*a(n-7) +254*a(n-8) +295*a(n-9) +1340*a(n-10) +1443*a(n-11) -482*a(n-12) -6615*a(n-13) -9530*a(n-14) -6728*a(n-15) +4516*a(n-16) +30043*a(n-17) +61608*a(n-18) +63827*a(n-19) -11283*a(n-20) -123492*a(n-21) -172940*a(n-22) -94417*a(n-23) +45861*a(n-24) +126286*a(n-25) +102719*a(n-26) +28878*a(n-27) -21731*a(n-28) -29644*a(n-29) -13860*a(n-30) -2169*a(n-31) +807*a(n-32) +1259*a(n-33) +1144*a(n-34) +409*a(n-35) -225*a(n-36) for n>39

Example

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

Crossrefs

Cf. A318222.

Sequence in context: A259880 A364524 A092473 * A073558 A132306 A264196

Adjacent sequences: A318215 A318216 A318217 * A318219 A318220 A318221

Keyword

nonn

Author

R. H. Hardin, Aug 21 2018

Status

approved