A234884 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 1, with no adjacent elements equal (constant-stress tilted 1 X 1 tilings).

272, 980, 3164, 11984, 40856, 159004, 551048, 2185372, 7639428, 30731272, 108061936, 439375016, 1551527016, 6358076852, 22519342100, 92803479508, 329391982880, 1362841851812, 4844325889344, 20098730525504, 71515038046716

Offset

1,1

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +46*a(n-2) -91*a(n-3) -852*a(n-4) +1670*a(n-5) +8364*a(n-6) -16318*a(n-7) -48531*a(n-8) +94856*a(n-9) +177211*a(n-10) -349287*a(n-11) -422181*a(n-12) +844527*a(n-13) +666796*a(n-14) -1362305*a(n-15) -697540*a(n-16) +1464198*a(n-17) +475379*a(n-18) -1029412*a(n-19) -204338*a(n-20) +455683*a(n-21) +52461*a(n-22) -118912*a(n-23) -7142*a(n-24) +16187*a(n-25) +376*a(n-26) -846*a(n-27).

Example

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

Crossrefs

Column 2 of A234890.

Sequence in context: A306134 A317269 A253113 * A158587 A304417 A316242

Adjacent sequences: A234881 A234882 A234883 * A234885 A234886 A234887

Keyword

nonn

Author

R. H. Hardin, Jan 01 2014

Status

approved