A297690 Number of nX4 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 0, 2 or 4 neighboring 1s.

8, 60, 293, 1774, 10647, 61054, 358972, 2106480, 12300234, 72038048, 421753983, 2467894885, 14445993705, 84556016585, 494899782183, 2896730371983, 16954908294495, 99238520202415, 580854325487284, 3399802583923881

Offset

1,1

Comments

Column 4 of A297694.

Links

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

Formula

Empirical: a(n) = 6*a(n-1) -a(n-2) +28*a(n-3) -175*a(n-4) +87*a(n-5) -113*a(n-6) +990*a(n-7) -665*a(n-8) +109*a(n-9) -1670*a(n-10) +1463*a(n-11) -100*a(n-12) +874*a(n-13) -1129*a(n-14) +190*a(n-15) +50*a(n-16) +183*a(n-17) -97*a(n-18) -111*a(n-19) +78*a(n-20) +6*a(n-21) -3*a(n-22) -3*a(n-23)

Example

Some solutions for n=6
..0..0..1..1. .0..0..0..0. .0..0..0..1. .0..1..0..1. .0..1..1..0
..0..1..1..0. .1..0..1..0. .0..1..0..0. .0..0..0..0. .0..1..1..0
..0..0..0..0. .0..0..0..0. .1..1..1..0. .1..0..0..0. .0..1..0..1
..0..0..0..1. .1..0..0..1. .0..0..0..0. .0..0..1..0. .0..1..1..1
..0..0..0..0. .1..0..0..0. .1..0..0..0. .0..1..0..1. .0..0..1..0
..0..1..0..1. .0..0..0..1. .1..0..1..0. .0..0..1..0. .1..0..0..0

Crossrefs

Cf. A297694.

Sequence in context: A250315 A074423 A199906 * A268599 A250556 A054401

Adjacent sequences: A297687 A297688 A297689 * A297691 A297692 A297693

Keyword

nonn

Author

R. H. Hardin, Jan 03 2018

Status

approved