OFFSET
0,3
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..8
FORMULA
MAPLE
doublefactorial(doublefactorial(n)) ; # R. J. Mathar, Feb 22 2009
MATHEMATICA
Factorial2[Factorial2[Range[0, 10]]] (* G. C. Greubel, Jan 07 2022 *)
PROG
(Magma)
DoubleFactorial:=func< n | &*[n..2 by -2] >; // A006882
[DoubleFactorial(DoubleFactorial(n)): n in [0..9] ]; // G. C. Greubel, Jan 07 2022
(Sage) [(n.multifactorial(2)).multifactorial(2) for n in (0..9)] # G. C. Greubel, Jan 07 2022
CROSSREFS
KEYWORD
nonn
AUTHOR
Aart Blokhuis (aartb(AT)win.tue.nl), Feb 20 2009
EXTENSIONS
Another term with fewer than 80 digits added by R. J. Mathar, Feb 22 2009
a(0) prepended by G. C. Greubel, Jan 07 2022
STATUS
approved