A234654 Number of (n+1) X (4+1) 0..5 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 4 (constant-stress 1 X 1 tilings).

15008, 37352, 94432, 274520, 808160, 2646344, 8731840, 31384136, 113059808, 437774312, 1689860992, 6944469320, 28298174240, 121873410344, 517811131840, 2312599876616, 10141883194208, 46569251868392, 209116100618752

Offset

1,1

Links

R. H. Hardin, Table of n, a(n) for n = 1..169

Formula

Empirical: a(n) = 8*a(n-1) +85*a(n-2) -820*a(n-3) -2645*a(n-4) +35720*a(n-5) +27415*a(n-6) -866260*a(n-7) +408982*a(n-8) +12858104*a(n-9) -16068980*a(n-10) -120659920*a(n-11) +221967320*a(n-12) +709627680*a(n-13) -1711158240*a(n-14) -2457267840*a(n-15) +7901564544*a(n-16) +4009471488*a(n-17) -21498324480*a(n-18) +987863040*a(n-19) +31468953600*a(n-20) -12541132800*a(n-21) -18911232000*a(n-22) +11943936000*a(n-23).

Example

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

Crossrefs

Column 4 of A234658.

Sequence in context: A064968 A178929 A145275 * A064730 A081635 A165614

Adjacent sequences: A234651 A234652 A234653 * A234655 A234656 A234657

Keyword

nonn

Author

R. H. Hardin, Dec 29 2013

Status

approved