A251253 - OEIS

The OEIS is supported by the many generous donors to the OEIS Foundation.

A251253

Number of (n+1) X (3+1) 0..1 arrays with every 2 X 2 subblock having a single 1 or two 1s on the same edge.

38, 150, 464, 1770, 5680, 21088, 69270, 252226, 842160, 3024532, 10215894, 36333498, 123729784, 437028516, 1496890470, 5261453226, 18095303560, 63384222948, 218626027574, 763932706666, 2640392321080, 9210217141124

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

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

FORMULA

Empirical: a(n) = a(n-1) + 13*a(n-2) - 7*a(n-3) - 32*a(n-4) + 8*a(n-5) + 10*a(n-6).

Empirical g.f.: 2*x*(19 + 56*x - 90*x^2 - 189*x^3 + 72*x^4 + 71*x^5) / (1 - x - 13*x^2 + 7*x^3 + 32*x^4 - 8*x^5 - 10*x^6). - Colin Barker, Nov 27 2018

EXAMPLE

Some solutions for n=4:

..1..1..0..1....1..1..1..0....1..1..1..1....0..0..0..1....0..0..0..0

..0..0..0..0....0..0..0..0....0..0..0..0....0..1..0..1....1..1..0..1

..1..0..1..0....0..1..1..1....0..1..1..1....0..0..0..0....0..0..0..0

..0..0..0..0....0..0..0..0....0..0..0..0....0..1..0..1....1..0..1..0

..1..1..0..1....0..1..0..1....1..1..1..0....0..0..0..0....1..0..1..0

CROSSREFS

Column 3 of A251258.

Sequence in context: A320309 A164093 A158064 * A224739 A135176 A318625

Adjacent sequences: A251250 A251251 A251252 * A251254 A251255 A251256

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 01 2014

STATUS

approved