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%I #10 Mar 02 2023 12:45:32
%S 1,2,6,168,6623019333730800000
%N a(1)=1; for n>=2, a(n) = Product_{d|a(n-1)} (d+1), where the product is over all positive divisors d of a(n-1).
%C The next term is a lot bigger than 70000! and is too large to include. - _Stefan Steinerberger_, Dec 31 2007
%e The positive divisors of a(3)=6 are 1,2,3,6. So a(4) = (1+1)*(2+1)*(3+1)*(6+1) = 2*3*4*7 = 168.
%t a = {1}; Do[AppendTo[a, Times @@ (Divisors[a[[ -1]]] + 1)], {4}]; a (* _Stefan Steinerberger_, Dec 31 2007 *)
%Y Cf. A135938.
%K nonn
%O 1,2
%A _Leroy Quet_, Dec 07 2007
%E a(5) from _Stefan Steinerberger_, Dec 31 2007
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