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%I #15 Aug 09 2021 18:03:34
%S 2,6,48,1240,46080,10537956,4755179520,21601740363840,
%T 320026934857728000,5141450783421628416000,
%U 254900463912224253775282176,22582740409889438693597632266240
%N a(n) = sigma(a(n-1)) * number of divisors of a(n-1), a(1)=2.
%H Harry J. Smith, <a href="/A063744/b063744.txt">Table of n, a(n) for n = 1..40</a>
%t NestList[DivisorSigma[1,#]DivisorSigma[0,#]&,2,15] (* _Harvey P. Dale_, Aug 09 2021 *)
%o (PARI) s(n) = if(n<2,n=2, sigma(s(n-1))*numdiv(s(n-1))); for(n=1,20,print(s(n)))
%o (PARI) { for (n=1, 40, if (n>1, a=sigma(a)*numdiv(a), a=2); write("b063744.txt", n, " ", a) ) } \\ _Harry J. Smith_, Aug 29 2009
%K easy,nonn
%O 1,1
%A _Jason Earls_, Aug 14 2001
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