A234171 Number of (n+1) X (2+1) 0..6 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 1 (constant-stress 1 X 1 tilings).

4536, 70486, 1173940, 20235390, 354809676, 6280203692, 111690695276, 1992506433044, 35594422747852, 636660168609324, 11391644399534828, 203967124960446932, 3652089234220796108, 65424063948417919724

Offset

1,1

Links

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

Formula

Empirical: a(n) = 33*a(n-1) +323*a(n-2) -20479*a(n-3) +66827*a(n-4) +4196961*a(n-5) -32408967*a(n-6) -381895309*a(n-7) +4395837462*a(n-8) +15113145790*a(n-9) -293548976068*a(n-10) -51289577932*a(n-11) +10922776315912*a(n-12) -16766805352904*a(n-13) -235952101172000*a(n-14) +626750889441184*a(n-15) +2967198544937088*a(n-16) -10881957631245888*a(n-17) -20625630149777664*a(n-18) +106077230575696640*a(n-19) +62012982701743616*a(n-20) -603993107147691008*a(n-21) +80220923857108992*a(n-22) +1983943732124129280*a(n-23) -1120944653090611200*a(n-24) -3571475321182953472*a(n-25) +3062535903549603840*a(n-26) +3148640202567516160*a(n-27) -3550878140723822592*a(n-28) -1004211355174305792*a(n-29) +1711073233311105024*a(n-30) -31999222443147264*a(n-31) -285978658647048192*a(n-32) +29150317966786560*a(n-33) +14870074192035840*a(n-34) -1882287872409600*a(n-35).

Example

Some solutions for n=2:
  3 6 3   6 4 4   4 1 4   3 5 4   4 6 3   5 5 3   3 2 5
  4 6 4   4 3 2   4 0 2   5 6 6   2 3 1   6 5 2   2 0 2
  0 1 0   6 6 4   4 1 2   2 2 1   2 4 1   3 3 1   6 3 4

Crossrefs

Column 2 of A234175.

Sequence in context: A250450 A339795 A337314 * A262848 A307919 A031607

Adjacent sequences: A234168 A234169 A234170 * A234172 A234173 A234174

Keyword

nonn

Author

R. H. Hardin, Dec 20 2013

Status

approved