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EXAMPLE
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Sieve starts with the natural numbers:
1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,...
Step 1: keep 1 term, remove the next 5, repeat; giving
1,7,13,19,25,31,37,43,49,55,61,67,73,79,...
Step 2: keep 2 terms, remove the next 5, repeat; giving
1,7,43,49,85,91,127,133,169,175,211,217,...
Step 3: keep 3 terms, remove the next 5, repeat; giving
1,7,43,169,175,211,337,343,379,505,511,547,...
Continuing in this way, we obtain this sequence.
Using the floor function product formula:
a(2) = 1+[..[(2)*2/1]*3/2]*4/3]*5/4]*7/6]*8/7]*9/8]*10/9]*
12/11]*13/12]*14/13]*15/14]*17/16]*18/17]*19/18]*20/19]*
22/21]*23/22]*24/23]*25/24]*27/26]*28/27]*29/28]*30/29] =43.
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