A234916 Number of (n+1) X (3+1) 0..4 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 2, with no adjacent elements equal (constant-stress tilted 1 X 1 tilings).

376, 1128, 3684, 13336, 49056, 186500, 710304, 2755840, 10693364, 42087616, 165680800, 659882692, 2629088000, 10575205872, 42553878500, 172546960864, 699893575232, 2856015808196, 11657898710352, 47806906114000

Offset

1,1

Links

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

Formula

Empirical: a(n) = 9*a(n-1) -2*a(n-2) -188*a(n-3) +413*a(n-4) +1077*a(n-5) -3828*a(n-6) -1678*a(n-7) +14385*a(n-8) -3643*a(n-9) -26998*a(n-10) +16004*a(n-11) +26132*a(n-12) -21362*a(n-13) -12072*a(n-14) +12608*a(n-15) +2016*a(n-16) -3096*a(n-17) +224*a(n-19).

Example

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

Crossrefs

Column 3 of A234921.

Sequence in context: A008853 A188007 A251644 * A288916 A198640 A171489

Adjacent sequences: A234913 A234914 A234915 * A234917 A234918 A234919

Keyword

nonn

Author

R. H. Hardin, Jan 01 2014

Status

approved