%I A034182
%S A034182 1,5,15,39,97,237,575,1391,3361,8117,19599,47319,114241,275805,665855,
%T A034182 1607519,3880897,9369317,22619535,54608391,131836321,318281037,
%U A034182 768398399,1855077839,4478554081,10812186005,26102926095,63018038199
%N A034182 Not necessarily symmetric n x 2 crossword puzzle grids.
%C A034182 n X 2 binary arrays with a path of adjacent 1's and no path of adjacent 
               0's from top row to bottom row. - Ron Hardin (rhhardin(AT)att.net), 
               Mar 21 2002
%F A034182 a(n) = 2a(n-1)+a(n-2)+4
%F A034182 a(n)=-2+(3/2)*[1+sqrt(2)]^(n-1)-sqrt(2)*[1-sqrt(2)]^(n-1)+(3/2)*[1-sqrt(2)]^(n-1)+[1+sqrt(2)]^(n-1) 
               *sqrt(2), with n>=1 - Paolo P. Lava (ppl(AT)spl.at), Jun 10 2008
%Y A034182 Sequence in context: A062487 A084447 A099035 this_sequence A132985 A022570 
               A152881
%Y A034182 Adjacent sequences: A034179 A034180 A034181 this_sequence A034183 A034184 
               A034185
%K A034182 nonn
%O A034182 1,2
%A A034182 Erich Friedman (erich.friedman(AT)stetson.edu)