A226845 - OEIS

%I #7 Sep 06 2018 09:09:04

%S 3,9,23,57,145,373,957,2449,6267,16045,41083,105185,269297,689465,

%T 1765209,4519393,11570803,29624209,75845551,194184025,497160801,

%U 1272858861,3258844373,8343475473,21361432171,54690732373,140022269235

%N Number of n X 1 (0,1,2) arrays of permanents of 2 X 2 subblocks of some (n+1) X 2 binary array.

%H R. H. Hardin, <a href="/A226845/b226845.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 3*a(n-1) - 2*a(n-2) + 2*a(n-3) + a(n-4) -a (n-5).

%F Empirical g.f.: x*(3 - x^2)*(1 + x^2) / (1 - 3*x + 2*x^2 - 2*x^3 - x^4 + x^5). - _Colin Barker_, Sep 06 2018

%e Some solutions for n=3:

%e ..0....2....0....1....2....1....1....2....0....2....0....0....2....1....2....0

%e ..0....1....1....2....2....1....2....1....0....2....2....1....0....1....2....2

%e ..2....1....0....1....1....0....2....0....0....2....2....1....0....2....0....1

%Y Column 1 of A226852.

%K nonn

%O 1,1

%A _R. H. Hardin_, Jun 19 2013