A167367 a(n) = sigma(n!!) where n!! is A006882(n).

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

G. C. Greubel, Table of n, a(n) for n = 0..500

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

Adjacent sequences: A167364 A167365 A167366 * A167368 A167369 A167370

Keyword

nonn

Author

Vladimir Joseph Stephan Orlovsky, Nov 01 2009

Status

approved