A163037 Number of nX2 binary arrays with all 1s connected and a path of 1s from left column to right column.

1, 7, 28, 88, 245, 639, 1608, 3968, 9689, 23527, 56964, 137720, 332717, 803519, 1940176, 4684352, 11309425, 27303815, 65917740, 159140056, 384198693, 927538367, 2239276440, 5406092352, 13051462345, 31509018343, 76069500436

Offset: 1

Author

R. H. Hardin Jul 20 2009

Keywords

• nonn

Comments

Sum of the elements in the first n rows of the triangle defined in the comment in A034182: 1; 3,3; 7,7,7;... (if the empirical recurrence is correct). - J. M. Bergot, Mar 22 2013

Links

• R. H. Hardin, Table of n, a(n) for n=1..100

Formula

Empirical: a(n)=5*a(n-1)-8*a(n-2)+4*a(n-3)+a(n-4)-a(n-5) = A001333(n+3)/2 -A097080(n+1)/2. G.f.: x*(1+x)^2/((x^2+2*x-1)*(x-1)^3). [From R. J. Mathar, Aug 11 2009]