A234885 Number of (n+1) X (3+1) 0..5 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 1, with no adjacent elements equal (constant-stress tilted 1 X 1 tilings).

856, 3164, 10640, 43680, 163352, 706992, 2734000, 12203144, 47902816, 218388912, 864693472, 4003619480, 15940068144, 74661520248, 298373769264, 1409767189888, 5648661963120, 26865714384208, 107846686617472, 515515002119648

Offset

1,1

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +86*a(n-2) -171*a(n-3) -3254*a(n-4) +6420*a(n-5) +72208*a(n-6) -140996*a(n-7) -1058026*a(n-8) +2037844*a(n-9) +10934873*a(n-10) -20686144*a(n-11) -83167418*a(n-12) +153691479*a(n-13) +479339096*a(n-14) -859425200*a(n-15) -2137842471*a(n-16) +3687468872*a(n-17) +7489913552*a(n-18) -12299566373*a(n-19) -20830586705*a(n-20) +32156843576*a(n-21) +46298748518*a(n-22) -66176437253*a(n-23) -82513440614*a(n-24) +107256565124*a(n-25) +117915942463*a(n-26) -136506202014*a(n-27) -134651989808*a(n-28) +135526272729*a(n-29) +121980787038*a(n-30) -103852594014*a(n-31) -86649823814*a(n-32) +60484275256*a(n-33) +47465104086*a(n-34) -26205941074*a(n-35) -19592874823*a(n-36) +8200629244*a(n-37) +5905922924*a(n-38) -1777329681*a(n-39) -1244167978*a(n-40) +250186878*a(n-41) +171453636*a(n-42) -20378088*a(n-43) -13746096*a(n-44) +723168*a(n-45) +482112*a(n-46).

Example

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

Crossrefs

Column 3 of A234890.

Sequence in context: A183998 A209502 A198527 * A251453 A087002 A256743

Adjacent sequences: A234882 A234883 A234884 * A234886 A234887 A234888

Keyword

nonn

Author

R. H. Hardin, Jan 01 2014

Status

approved