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A167368 a(n) = sigma((n!!)!). 2
1, 1, 3, 12, 159120, 6686252969760, 89050715142739003008099466232718435351438398888454549774336000 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Table of n, a(n) for n=0..6.

FORMULA

a(n) = A000203(A161563(n)).

MATHEMATICA

Array[DivisorSigma[1, #!!! ]&, 7, 1]

PROG

(PARI) A167368(n)=sigma( prod(k=0, n\2-1, n-2*k) ! )  \\ M. F. Hasler, Feb 07 2011

CROSSREFS

Cf. A062569, A167367.

Sequence in context: A169815 A239891 A226129 * A318165 A215240 A068697

Adjacent sequences:  A167365 A167366 A167367 * A167369 A167370 A167371

KEYWORD

nonn,less

AUTHOR

Vladimir Joseph Stephan Orlovsky, Nov 01 2009

EXTENSIONS

a(0)=1 prepended by Alois P. Heinz, Jan 12 2022

STATUS

approved

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Last modified October 3 22:17 EDT 2022. Contains 357237 sequences. (Running on oeis4.)