A235019 Number of (n+1) X (1+1) 0..5 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 3, with no adjacent elements equal (constant-stress tilted 1 X 1 tilings).

88, 332, 1248, 4704, 17728, 66848, 252032, 950464, 3583744, 13515392, 50960896, 192190208, 724671488, 2732976640, 10304956416, 38863420416, 146538360832, 552644962304, 2083802423296, 7858713030656, 29632054018048, 111752346116096

Offset

1,1

Links

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

Formula

Empirical: a(n) = 18*a(n-2) - 56*a(n-4) + 32*a(n-6).

Empirical g.f.: 4*x*(22 + 83*x - 84*x^2 - 318*x^3 + 48*x^4 + 192*x^5) / (1 - 18*x^2 + 56*x^4 - 32*x^6). - Colin Barker, Oct 17 2018

Example

Some solutions for n=4:
  0 1   0 4   4 2   0 4   2 0   4 2   1 2   5 0   4 3   1 5
  4 2   2 3   3 4   2 3   1 2   3 4   3 1   3 1   0 2   2 3
  3 4   3 1   1 5   3 1   2 0   2 0   1 2   1 2   1 0   1 5
  4 2   2 3   2 3   4 5   0 1   1 2   5 3   0 4   0 2   2 3
  5 0   3 1   1 5   3 1   2 0   5 3   4 5   4 5   2 1   1 5

Crossrefs

Column 1 of A235026.

Sequence in context: A003782 A235026 A323612 * A241846 A064022 A116065

Adjacent sequences: A235016 A235017 A235018 * A235020 A235021 A235022

Keyword

nonn

Author

R. H. Hardin, Jan 02 2014

Status

approved