A235314 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 7 (constant-stress 1 X 1 tilings).

1120, 2744, 5968, 16352, 40144, 118160, 316912, 978320, 2793040, 8912144, 26587888, 86877392, 267503824, 889483280, 2803453552, 9443848400, 30295673680, 103054014224, 335138253808, 1148358087632, 3774606372304, 13004580227600

Offset

1,1

Comments

Column 3 of A235319.

Links

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

Formula

Empirical: a(n) = 4*a(n-1) +47*a(n-2) -200*a(n-3) -901*a(n-4) +4204*a(n-5) +8957*a(n-6) -48440*a(n-7) -47194*a(n-8) +334096*a(n-9) +101948*a(n-10) -1410080*a(n-11) +170136*a(n-12) +3549696*a(n-13) -1446912*a(n-14) -4861440*a(n-15) +2954880*a(n-16) +2764800*a(n-17) -2073600*a(n-18).

Example

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

Crossrefs

Sequence in context: A134211 A171004 A235275 * A340790 A237689 A032777

Adjacent sequences: A235311 A235312 A235313 * A235315 A235316 A235317

Keyword

nonn

Author

R. H. Hardin, Jan 05 2014

Status

approved