A235082 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 4, with no adjacent elements equal (constant-stress tilted 1 X 1 tilings).

202, 418, 830, 1758, 3610, 7810, 16390, 36014, 76770, 170682, 368326, 826742, 1802794, 4080058, 8981550, 20478862, 45484138, 104423170, 233911958, 540447918, 1220542066, 2836640986, 6456060310, 15085064246, 34583105082, 81197167002

Offset

1,1

Links

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

Formula

Empirical: a(n) = 5*a(n-1) +9*a(n-2) -78*a(n-3) +12*a(n-4) +462*a(n-5) -368*a(n-6) -1304*a(n-7) +1433*a(n-8) +1841*a(n-9) -2237*a(n-10) -1346*a(n-11) +1420*a(n-12) +604*a(n-13) -300*a(n-14) -120*a(n-15).

Example

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

Crossrefs

Column 3 of A235087.

Sequence in context: A066130 A067335 A356881 * A260280 A252993 A252987

Adjacent sequences: A235079 A235080 A235081 * A235083 A235084 A235085

Keyword

nonn

Author

R. H. Hardin, Jan 03 2014

Status

approved