A235194 Number of (n+1) X (4+1) 0..6 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 5, with no adjacent elements equal (constant-stress tilted 1 X 1 tilings).

7072, 15604, 35868, 96848, 261760, 774140, 2263256, 7020392, 21497244, 68985912, 218669280, 722516636, 2358872824, 8004360008, 26827441196, 93250959800, 319805488320, 1135256499660, 3969864602232, 14343676192424, 50961119662300

Offset

1,1

Links

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

Formula

Empirical: a(n) = 9*a(n-1) +57*a(n-2) -731*a(n-3) -878*a(n-4) +26304*a(n-5) -15900*a(n-6) -552844*a(n-7) +899723*a(n-8) +7521105*a(n-9) -18125633*a(n-10) -69122561*a(n-11) +220983779*a(n-12) +431291855*a(n-13) -1831340243*a(n-14) -1746606119*a(n-15) +10803108780*a(n-16) +3716404250*a(n-17) -46315168788*a(n-18) +2550194940*a(n-19) +145490417695*a(n-20) -46954531755*a(n-21) -335197745077*a(n-22) +166429786799*a(n-23) +564880422518*a(n-24) -334400168840*a(n-25) -694120308016*a(n-26) +424547635156*a(n-27) +620744392928*a(n-28) -343613520080*a(n-29) -401608244880*a(n-30) +170947437904*a(n-31) +182786646240*a(n-32) -46865973504*a(n-33) -54609655680*a(n-34) +4665398976*a(n-35) +9369063936*a(n-36) +551978496*a(n-37) -679311360*a(n-38) -113218560*a(n-39).

Example

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

Crossrefs

Column 4 of A235198.

Sequence in context: A230975 A031582 A063057 * A034230 A183630 A357478

Adjacent sequences: A235191 A235192 A235193 * A235195 A235196 A235197

Keyword

nonn

Author

R. H. Hardin, Jan 04 2014

Status

approved