login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A303417
Number of nX4 0..1 arrays with every element equal to 0, 1, 2, 3, 4 or 5 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
1
8, 128, 1985, 30897, 480960, 7486369, 116529645, 1813851698, 28233652317, 439473157219, 6840654335738, 106478748377005, 1657403414891639, 25798444493138200, 401567736789419233, 6250634501358061189
OFFSET
1,1
COMMENTS
Column 4 of A303421.
LINKS
FORMULA
Empirical: a(n) = 14*a(n-1) +21*a(n-2) +54*a(n-3) -23*a(n-4) -18*a(n-5) -20*a(n-6)
EXAMPLE
Some solutions for n=5
..0..0..0..0. .0..0..0..0. .0..0..0..0. .0..0..0..1. .0..0..0..0
..1..0..1..1. .0..0..0..0. .0..1..1..0. .1..0..1..0. .1..1..1..0
..0..0..0..1. .1..1..1..1. .1..1..1..1. .0..1..1..1. .0..1..0..1
..0..1..1..1. .0..0..0..0. .0..0..1..0. .0..0..1..1. .1..0..0..0
..1..1..1..0. .0..0..0..1. .0..1..0..1. .1..1..0..1. .0..0..0..1
CROSSREFS
Cf. A303421.
Sequence in context: A299650 A300204 A213414 * A303423 A301403 A317513
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 23 2018
STATUS
approved