A069307 Number of 3 X n binary arrays with a path of adjacent 1's from upper left corner to anywhere in right hand column.

21, 110, 581, 3070, 16227, 85776, 453423, 2396868, 12670261, 66977242, 354053617, 1871590506, 9893561055, 52299127660, 276462513603, 1461430140016, 7725380293233, 40837737667414, 215875562691877

Offset: 2

Author

R. H. Hardin, Mar 14 2002

Keywords

• nonn

Crossrefs

Cf. 2 X n A069306, 4 X n A069308, 5 X n A069309, 6 X n A069310, 7 X n A069311, 8 X n A069312, 9 X n A069313, 10 X n A069314, 11 X n A069315, 12 X n A069316, 13 X n A069317, 14 X n A069318, 15 X n A069319, 16 X n A069320, by columns A069294-A069305.

Formula

G.f.: x^2*(21-37*x+14*x^3-8*x^4)/(1+2*x^5-7*x+9*x^2+x^3-4*x^4). - Vladeta Jovovic, Jul 02 2003