A320360 Number of nX4 0..1 arrays with every element unequal to 2, 3, 4 or 6 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

0, 2, 13, 97, 657, 4563, 32371, 228784, 1612859, 11374902, 80252806, 566175160, 3994098794, 28176649157, 198775593337, 1402285633511, 9892577717775, 69788278801521, 492329166184534, 3473190776781317, 24502009569701222

Offset

1,2

Comments

Column 4 of A320364.

Links

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

Formula

Empirical: a(n) = 10*a(n-1) -31*a(n-2) +99*a(n-3) -179*a(n-4) -98*a(n-5) +318*a(n-6) -1515*a(n-7) +1949*a(n-8) +5942*a(n-9) -3459*a(n-10) +5623*a(n-11) +10531*a(n-12) -49890*a(n-13) -53973*a(n-14) -25336*a(n-15) -80965*a(n-16) +27765*a(n-17) +310873*a(n-18) +461224*a(n-19) +592511*a(n-20) +626252*a(n-21) +91305*a(n-22) -894877*a(n-23) -2087649*a(n-24) -3059547*a(n-25) -3232205*a(n-26) -2201891*a(n-27) -72523*a(n-28) +2710429*a(n-29) +5157028*a(n-30) +6352515*a(n-31) +6080953*a(n-32) +4575847*a(n-33) +2428433*a(n-34) +438133*a(n-35) -948313*a(n-36) -1550855*a(n-37) -1486686*a(n-38) -1102769*a(n-39) -654594*a(n-40) -215740*a(n-41) +39378*a(n-42) +107008*a(n-43) +97334*a(n-44) +81299*a(n-45) +29802*a(n-46) -2580*a(n-47) -3739*a(n-48) -1016*a(n-49) -2709*a(n-50) -1053*a(n-51) +92*a(n-52) +101*a(n-53) -13*a(n-54) +16*a(n-55) -4*a(n-56) for n>58

Example

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

Crossrefs

Cf. A320364.

Sequence in context: A369202 A118352 A372891 * A074614 A184019 A300633

Adjacent sequences: A320357 A320358 A320359 * A320361 A320362 A320363

Keyword

nonn

Author

R. H. Hardin, Oct 11 2018

Status

approved