A235020 Number of (n+1) X (2+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).

332, 1200, 4312, 15572, 56276, 203768, 738516, 2680636, 9738960, 35432228, 129023908, 470470536, 1717000260, 6274522924, 22948524144, 84039182132, 308005315508, 1130228790408, 4150565943156, 15260094453244, 56146361267440

Offset

1,1

Links

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

Formula

Empirical: a(n) = 5*a(n-1) +40*a(n-2) -213*a(n-3) -616*a(n-4) +3529*a(n-5) +4898*a(n-6) -29657*a(n-7) -24043*a(n-8) +140862*a(n-9) +80302*a(n-10) -394226*a(n-11) -183852*a(n-12) +650340*a(n-13) +268328*a(n-14) -614608*a(n-15) -222048*a(n-16) +318656*a(n-17) +91776*a(n-18) -82432*a(n-19) -14336*a(n-20) +8192*a(n-21).

Example

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

Crossrefs

Column 2 of A235026.

Sequence in context: A250758 A114084 A257892 * A111690 A095199 A158081

Adjacent sequences: A235017 A235018 A235019 * A235021 A235022 A235023

Keyword

nonn

Author

R. H. Hardin, Jan 02 2014

Status

approved