A204912 Ordered differences of double factorials.

1, 2, 1, 7, 6, 5, 14, 13, 12, 7, 47, 46, 45, 40, 33, 104, 103, 102, 97, 90, 57, 383, 382, 381, 376, 369, 336, 279, 944, 943, 942, 937, 930, 897, 840, 561, 3839, 3838, 3837, 3832, 3825, 3792, 3735, 3456, 2895, 10394, 10393, 10392, 10387, 10380

Offset: 1

Author

Clark Kimberling, Jan 22 2012

Keywords

• nonn

Comments

For a guide to related sequences, see A204892.

As a triangle with rows {1}, {2,1}, {7,6,5}, ..., evidently the first diagonal is A007911 = {1,1,5,7,33,57,279,...} (up to an offset). - L. Edson Jeffery, Jan 24 2012

Examples

			a(1)=2!!-1!!=2-1=1
a(2)=3!!-1!!=3-1=2
a(3)=3!!-2!!=3-2=1
a(4)=4!!-1!!=8-1=7
a(5)=4!!-2!!=8-2=6
		

Crossrefs

Cf. A204982, A204892.

Cf. A007911.

Programs

Mathematica

(See the program at A204982.)