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A129981
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Sum of n!!, with n>=0.
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2
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1, 2, 4, 7, 15, 30, 78, 183, 567, 1512, 5352, 15747, 61827, 196962, 842082, 2869107, 13191027, 47650452, 233445012, 888174087, 4604065287, 18353375862, 100102982262, 416337125487, 2378327679087, 10284181259712, 61295935653312
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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COMMENTS
| Partial sums of A006882.
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EXAMPLE
| 0!!=1
1!!=1 -> 1+1=2
2!!=2 -> 2+2=4
3!!=3 -> 4+3=7
4!!=8 -> 7+8=15
5!!=15 -> 15+15=30
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MAPLE
| A129981 := proc(n)
add(doublefactorial(m), m=0..n) ;
end proc: # R. J. Mathar, Oct 11 2011
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MATHEMATICA
| s = 0; lst = {}; Do[s += n!!; AppendTo[lst, s], {n, 0, 26, 1}]; lst [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Jul 10 2009]
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CROSSREFS
| Sequence in context: A115178 A049885 A129682 * A072964 A030033 A135131
Adjacent sequences: A129978 A129979 A129980 * A129982 A129983 A129984
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KEYWORD
| easy,nonn
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AUTHOR
| Paolo P. Lava & Giorgio Balzarotti (paoloplava(AT)gmail.com), Jun 14 2007
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