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A204912 Ordered differences of double factorials. 1
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 (list; graph; refs; listen; history; text; internal format)
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

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Last modified October 19 14:00 EDT 2021. Contains 348090 sequences. (Running on oeis4.)