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%I #3 May 07 2013 10:10:24
%S 1,3,9,15,45,75,105,315,525,735,945,1155,3465,5775,8085,10395,12705,
%T 15015,45045,75075,105105,135135,165165,195195,225225,255255,765765,
%U 1276275,1786785,2297295,2807805,3318315,3828825,4339335,4849845
%N Boundaries of primorial intervals [1,3]; [3,9],[9,15]; [15,45], etc.
%F a(n+1)= a(n)+q(j) for primorial q(j) < a(n+1) <= q(j+1)/2.
%e a(4)= 15= a(3)+q(2)= 9+ 6, a(7)= 105= a(6)+q(3)= 75+ 30,
%e a(5)= 45= a(4)+q(3)=15+30, a(8)= 315= a(7)+q(4)=105+210.
%Y Primorial q(j)= A002110(j), interval count A005521(j+1)-1.
%K nonn,easy
%O 1,2
%A _Frank Ellermann_, Dec 08 2001
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