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a(n) = sigma((n!!)!).
2

%I #16 Jan 12 2022 11:37:26

%S 1,1,3,12,159120,6686252969760,

%T 89050715142739003008099466232718435351438398888454549774336000

%N a(n) = sigma((n!!)!).

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

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

%o (PARI) A167368(n)=sigma( prod(k=0,n\2-1,n-2*k) ! ) \\ _M. F. Hasler_, Feb 07 2011

%Y Cf. A062569, A167367.

%K nonn,less

%O 0,3

%A _Vladimir Joseph Stephan Orlovsky_, Nov 01 2009

%E a(0)=1 prepended by _Alois P. Heinz_, Jan 12 2022