A234821 Number of (n+1) X (6+1) 0..6 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 6 (constant-stress 1 X 1 tilings).

139112, 252486, 443220, 994812, 2099300, 5441232, 13185612, 37597992, 100759412, 307659576, 887665260, 2856356952, 8711766260, 29230410072, 93082415532, 323139754392, 1065130800692, 3802624291416, 12891708917100, 47097845952792

Offset

1,1

Links

R. H. Hardin, Table of n, a(n) for n = 1..34

Formula

Empirical: a(n) = 8*a(n-1) +60*a(n-2) -620*a(n-3) -1210*a(n-4) +20740*a(n-5) +1580*a(n-6) -392180*a(n-7) +353267*a(n-8) +4606324*a(n-9) -7135240*a(n-10) -34677440*a(n-11) +72387960*a(n-12) +165390560*a(n-13) -443380480*a(n-14) -464032320*a(n-15) +1696321584*a(n-16) +566607168*a(n-17) -3948347520*a(n-18) +465384960*a(n-19) +5084985600*a(n-20) -2142028800*a(n-21) -2757888000*a(n-22) +1741824000*a(n-23).

Example

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

Crossrefs

Column 6 of A234823.

Sequence in context: A236276 A250713 A236063 * A221669 A145207 A236745

Adjacent sequences: A234818 A234819 A234820 * A234822 A234823 A234824

Keyword

nonn

Author

R. H. Hardin, Dec 31 2013

Status

approved