A210149 1/4 the number of (n+1) X 2 0..3 arrays with every 2 X 2 subblock having one, three or four distinct clockwise edge differences.

57, 820, 11783, 169343, 2433709, 34976109, 502659771, 7223984325, 103819625131, 1492045676385, 21442962225379, 308167930976177, 4428841159329331, 63649173203875529, 914735278099257547, 13146135085198398465

Offset

1,1

Comments

Column 1 of A210156.

Links

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

Formula

Empirical: a(n) = 11*a(n-1) + 46*a(n-2) + 36*a(n-3) - 10*a(n-4) - 8*a(n-5).

Empirical g.f.: x*(57 + 193*x + 141*x^2 - 42*x^3 - 32*x^4) / (1 - 11*x - 46*x^2 - 36*x^3 + 10*x^4 + 8*x^5). - Colin Barker, Jul 14 2018

Example

Some solutions for n=4:
  0 0   2 3   2 0   3 2   1 1   1 0   1 3   3 2   1 1   3 1
  1 0   3 0   3 0   3 0   2 2   0 0   1 3   3 1   3 1   3 1
  0 2   0 2   2 0   1 1   1 0   0 3   3 2   1 2   0 0   3 3
  1 3   1 3   3 1   1 1   0 3   1 3   1 3   0 2   1 0   3 1
  3 0   2 0   1 2   2 1   0 0   1 0   0 1   0 0   2 0   1 1

Crossrefs

Cf. A210156.

Sequence in context: A241967 A098995 A210156 * A254783 A233370 A008390

Adjacent sequences: A210146 A210147 A210148 * A210150 A210151 A210152

Keyword

nonn

Author

R. H. Hardin, Mar 18 2012

Status

approved