A046222 First numerator and then denominator of central elements of 1/2-Pascal triangle.

1, 1, 1, 2, 3, 1, 11, 1, 40, 1, 147, 1, 546, 1, 2046, 1, 7722, 1, 29315, 1, 111826, 1, 428298, 1, 1646008, 1, 6344366, 1, 24515700, 1, 94942620, 1, 368404110, 1, 1431985635, 1, 5574725970, 1, 21732560850, 1, 84828633120, 1, 331488081210, 1

Offset: 1

Author

Mohammad K. Azarian

Keywords

• nonn

Examples

			1/1; 1/1 1/1; 1/1 1/2 1/1; 1/1 3/2 3/2 1/1; 1/1 5/2 3/1 5/2 1/1; 1/1 7/2 11/2 11/2 7/2 1/1; 1/1 9/2 9/1 11/1 9/1 9/2 1/1; 1/1 11/2 27/2 20/1 20/1 27/2 11/2 1/1; ...
		

Crossrefs

Cf. A046213.

Extensions

More terms from James Sellers, Dec 13 1999