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

2,1

Links

Table of n, a(n) for n=2..20.

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

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.

Sequence in context: A222347 A039611 A353622 * A157886 A039456 A182827

Adjacent sequences: A069304 A069305 A069306 * A069308 A069309 A069310

Keyword

nonn

Author

R. H. Hardin, Mar 14 2002

Status

approved