%I A072181
%S A072181 1,2,6,12,60,60,420,6720,20160,20160,221760,14192640,184504320,
%T A072181 184504320,184504320,12679040325931499520,215543685540835491840,
%U A072181 1939893169867519426560,36857970227482869104640
%N A072181 a(1) = 1; for n >= 2, suppose a(n-1) = Product p_i^e_i and n = Product 
               p_i^f_i, then a(n) = Product p_i^(e_i*f_i).
%F A072181 Let m = Product (p_i)^(e_{i, m}), m=1, 2, ..., where p_i is i_th prime. 
               Then a(n) = Product_{i=1..inf} (p_i)^(Product_{m =1..n} (e_{i, m})).
%F A072181 Let m = Product (p_i)^(e_{i, m}), m=1, 2, ..., where p_i is i_th prime. 
               Then a(n) = Product_{i=1..inf} (p_i)^(Product_{m =1..n}[max(1, e_{i, 
               m})]). - David Wasserman (wasserma(AT)spawar.navy.mil), Sep 07 2004
%e A072181 n=12: a(11) = 221760 = 2^6 3^2 5 7 11, 12 = 2^2 3^1, so a(12) = 2^(2*6) 
               3^(1*1) 5 7 11 = 14192640.
%Y A072181 Sequence in context: A003418 A109935 A065887 this_sequence A126915 A002201 
               A004490
%Y A072181 Adjacent sequences: A072178 A072179 A072180 this_sequence A072182 A072183 
               A072184
%K A072181 nonn,easy,nice
%O A072181 1,2
%A A072181 Naohiro Nomoto (n_nomoto(AT)yabumi.com), Jun 30 2002