A234186 Number of (n+1) X (2+1) 0..6 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 2 (constant-stress 1 X 1 tilings).

3710, 44826, 549448, 6788640, 83845322, 1039633348, 12874230598, 160028488122, 1986351882576, 24751815034582, 307960587879042, 3847220085760804, 47982564103428062, 600977948816485342, 7513780713855509152

Offset

1,1

Links

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

Formula

Empirical: a(n) = 35*a(n-1) +77*a(n-2) -15290*a(n-3) +107332*a(n-4) +2296310*a(n-5) -27496928*a(n-6) -129857668*a(n-7) +2709179565*a(n-8) +391078819*a(n-9) -135239185825*a(n-10) +266375054090*a(n-11) +3713789361020*a(n-12) -12460625596968*a(n-13) -56580508651576*a(n-14) +270946287990468*a(n-15) +430387300568260*a(n-16) -3285582832195460*a(n-17) -625640021406580*a(n-18) +23032403778290512*a(n-19) -13906330678694208*a(n-20) -92444778106408560*a(n-21) +104815576682548656*a(n-22) +206598724089786048*a(n-23) -335917036867402368*a(n-24) -235981789165139328*a(n-25) +576403492940640000*a(n-26) +84728859623294976*a(n-27) -554012779297904640*a(n-28) +82836671758755840*a(n-29) +287793157283389440*a(n-30) -93776254720819200*a(n-31) -69280227459072000*a(n-32) +30100904460288000*a(n-33) +4361304342528000*a(n-34) -2076811591680000*a(n-35).

Example

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

Crossrefs

Column 2 of A234190.

Sequence in context: A252694 A184471 A249655 * A179623 A263035 A252161

Adjacent sequences: A234183 A234184 A234185 * A234187 A234188 A234189

Keyword

nonn

Author

R. H. Hardin, Dec 20 2013

Status

approved