This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A100586 #12 May 13 2015 11:58:01
%S A100586 3,4,5,6,7,9,11,14,17,21,26,32,40,50,62,77,96,120,150,187,234,292,365,
%T A100586 456,570,712,890,1112,1390,1737,2171,2714,3392,4240,5300,6625,8281,
%U A100586 10351,12939,16174,20217,25271,31589,39486,49357,61696,77120
%N A100586 Write down the numbers from 3 to infinity. Take next number, M say, that has not been crossed off. Counting through the numbers that have not yet been crossed off after that M, cross off every 5th term. Repeat, always crossing off every 5th term of those that remain. The numbers that are left form the sequence.
%H A100586 Popular Computing (Calabasas, CA), <a href="/A003309/a003309.pdf">Sieves: Problem 43</a>, Vol. 2 (No. 13, Apr 1974), pp. 6-7. This is Sieve #6 with K=5. [Annotated and scanned copy]
%H A100586 <a href="/index/Si#sieve">Index entries for sequences generated by sieves</a>
%t A100586 t = Range[3, 80000]; r = {}; While[Length[t] > 0, AppendTo[r, First[t]]; t = Drop[t, {1, -1, 5}];]; r (* _Ray Chandler_, Dec 02 2004 *)
%Y A100586 Cf. A003309, A003310, A100464, A100562, A003312, A003311, A052548, A100585.
%K A100586 nonn
%O A100586 1,1
%A A100586 _N. J. A. Sloane_, Dec 01 2004