A234685 Number of (n+1) X (3+1) 0..6 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 5 (constant-stress 1 X 1 tilings).

5472, 16580, 49480, 174320, 603480, 2377712, 9134920, 39076784, 161746392, 735721040, 3215956360, 15315962480, 69679216920, 343388819792, 1608412346440, 8129729322224, 38891607413592, 200295926555600, 972926911960840

Offset

1,1

Links

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

Formula

Empirical: a(n) = 8*a(n-1) +136*a(n-2) -1228*a(n-3) -7714*a(n-4) +83412*a(n-5) +227220*a(n-6) -3310020*a(n-7) -3144813*a(n-8) +85322244*a(n-9) -10139052*a(n-10) -1502272464*a(n-11) +1272592288*a(n-12) +18484107136*a(n-13) -25856757520*a(n-14) -159615082880*a(n-15) +298588477264*a(n-16) +954259846848*a(n-17) -2239825910784*a(n-18) -3795391531008*a(n-19) +11239750642176*a(n-20) +9072344881152*a(n-21) -37315540684800*a(n-22) -8727234969600*a(n-23) +78238462464000*a(n-24) -12303747072000*a(n-25) -93182607360000*a(n-26) +40370503680000*a(n-27) +47656304640000*a(n-28) -30098718720000*a(n-29).

Example

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

Crossrefs

Column 3 of A234690.

Sequence in context: A232037 A202776 A324215 * A031572 A045108 A251962

Adjacent sequences: A234682 A234683 A234684 * A234686 A234687 A234688

Keyword

nonn

Author

R. H. Hardin, Dec 29 2013

Status

approved