A259421 - OEIS

A259421

Number of (n+1) X (2+1) 0..1 arrays with each 2 X 2 subblock having clockwise pattern 0000 0001 0011 or 0111.

43, 243, 1366, 7695, 43347, 244228, 1376077, 7753553, 43687910, 246163281, 1387029593, 7815349472, 44036333771, 248126951851, 1398095180302, 7877701886559, 44387669863035, 250106600625676, 1409249728938893

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OFFSET

1,1

LINKS

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

FORMULA

Empirical: a(n) = 6*a(n-1) + 2*a(n-2) - 22*a(n-3) - 6*a(n-4) + 6*a(n-5) + a(n-6).

Empirical g.f.: x*(43 - 15*x - 178*x^2 - 41*x^3 + 49*x^4 + 8*x^5) / (1 - 6*x - 2*x^2 + 22*x^3 + 6*x^4 - 6*x^5 - x^6). - Colin Barker, Dec 25 2018

EXAMPLE

Some solutions for n=4:

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

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

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

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

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

CROSSREFS

Column 2 of A259427.

Sequence in context: A362407 A158080 A142450 * A202008 A258214 A262915

Adjacent sequences: A259418 A259419 A259420 * A259422 A259423 A259424

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jun 26 2015

STATUS

approved