A234985 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 2, with no adjacent elements equal (constant-stress tilted 1 X 1 tilings).

370, 1490, 6908, 35598, 189200, 1026784, 5628414, 31099742, 172847074, 965377320, 5413449562, 30458642240, 171852511344, 971861068470, 5506551903798, 31249010774954, 177562598216536, 1010006437847702, 5750035704258456

Offset

1,1

Links

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

Formula

Empirical: a(n) = 10*a(n-1) +9*a(n-2) -317*a(n-3) +216*a(n-4) +4392*a(n-5) -4481*a(n-6) -34461*a(n-7) +37067*a(n-8) +168161*a(n-9) -177688*a(n-10) -531245*a(n-11) +547375*a(n-12) +1099678*a(n-13) -1121930*a(n-14) -1478131*a(n-15) +1530027*a(n-16) +1252813*a(n-17) -1355278*a(n-18) -636426*a(n-19) +748324*a(n-20) +180286*a(n-21) -245436*a(n-22) -25096*a(n-23) +44796*a(n-24) +1272*a(n-25) -4080*a(n-26) +144*a(n-28).

Example

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

Crossrefs

Column 2 of A234991.

Sequence in context: A161020 A102618 A225104 * A264895 A283359 A254288

Adjacent sequences: A234982 A234983 A234984 * A234986 A234987 A234988

Keyword

nonn

Author

R. H. Hardin, Jan 02 2014

Status

approved