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A167367
a(n) = sigma(n!!) where n!! is A006882(n).
3
1, 1, 3, 4, 15, 24, 124, 192, 1020, 1920, 12264, 23040, 159666, 322560, 2555280, 5041344, 40893840, 90744192, 761260368, 1814883840, 15732804296, 38900010240, 377587663200, 933600245760, 9087075973248, 23520702965760, 254438142416640
OFFSET
0,3
LINKS
FORMULA
a(n) = A000203(A006882(n)). - R. J. Mathar, Feb 07 2011
MATHEMATICA
Join[{1}, Array[DivisorSigma[1, #!! ]&, 50, 1]]
PROG
(PARI) a(n)=sigma(prod(i=0, (n-1)\2, n - 2*i )) \\ Charles R Greathouse IV, May 01 2016
CROSSREFS
Cf. A062569.
Sequence in context: A290863 A086826 A081405 * A024858 A293047 A135100
KEYWORD
nonn
AUTHOR
STATUS
approved