Table of n, a(n) for n=1..6.
Chaim Goodman-Strauss, Notes on the number of m × n binary arrays with all 1’s connected and a path of 1’s from top row to bottom row (May 21 2020)
Chaim Goodman-Strauss, Mma notebook to accompany the above document
For a formula see the Goodman-Strauss links. - N. J. A. Sloane, May 22 2020
Sequence in context: A209275 A199355 A290819 * A184136 A101994 A201004
Adjacent sequences: A163032 A163033 A163034 * A163036 A163037 A163038
R. H. Hardin Jul 20 2009