A235092 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 4, with no adjacent elements equal (constant-stress tilted 1 X 1 tilings).

256, 656, 1728, 4820, 13624, 39884, 117488, 354588, 1072888, 3306172, 10189840, 31866620, 99499864, 314460540, 990959472, 3155587516, 10009630136, 32048121852, 102135500880, 328299662204, 1049814687640, 3384204174332

Offset

1,1

Links

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

Formula

Empirical: a(n) = 6*a(n-1) +20*a(n-2) -178*a(n-3) -45*a(n-4) +2028*a(n-5) -1568*a(n-6) -11316*a(n-7) +15017*a(n-8) +32278*a(n-9) -57324*a(n-10) -42818*a(n-11) +104201*a(n-12) +14456*a(n-13) -82056*a(n-14) +10920*a(n-15) +16380*a(n-16).

Example

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

Crossrefs

Column 2 of A235098.

Sequence in context: A260065 A329488 A086061 * A237015 A237008 A045057

Adjacent sequences: A235089 A235090 A235091 * A235093 A235094 A235095

Keyword

nonn

Author

R. H. Hardin, Jan 03 2014

Status

approved