A206467 Number of (n+1) X 4 0..2 arrays with every 2 X 2 subblock having zero permanent.

441, 11025, 110889, 1896129, 23707161, 356190129, 4803737481, 69030731169, 955680252921, 13523866505361, 188928681187689, 2659384141993089, 37267791691450329, 523625523775949169, 7345838128808607561

Offset

1,1

Comments

Column 3 of A206472.

Links

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

Formula

Empirical: a(n) = 15*a(n-1) + 54*a(n-2) - 1116*a(n-3) + 1728*a(n-4) + 10368*a(n-5) - 20736*a(n-6).

Empirical g.f.: 9*x*(49 + 490*x - 8700*x^2 + 14400*x^3 + 91008*x^4 - 186624*x^5) / ((1 - 21*x + 108*x^2 - 144*x^3)*(1 + 6*x - 36*x^2 - 144*x^3)). - _Colin Barker_, Jun 16 2018

Example

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

Crossrefs

Cf. A206472.

Sequence in context: A014793 A264305 A321337 * A264262 A232003 A221248

Adjacent sequences: A206464 A206465 A206466 * A206468 A206469 A206470

Keyword

nonn

Author

_R. H. Hardin_, Feb 08 2012

Status

approved