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

1,2

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

Links

Table of n, a(n) for n=1..50.

Example

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

Mathematica

(See the program at A204982.)

Crossrefs

Cf. A204982, A204892.

Cf. A007911.

Sequence in context: A329058 A078301 A160201 * A178049 A257577 A060583

Adjacent sequences: A204909 A204910 A204911 * A204913 A204914 A204915

Keyword

nonn

Author

Clark Kimberling, Jan 22 2012

Status

approved