cp's OEIS Frontend

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.

A099207 A variation on Flavius's sieve (A000960): Start with the primes; at the k-th sieving step, remove every (k+1)-st term of the sequence remaining after the (k-1)-st sieving step; iterate.

Original entry on oeis.org

2, 5, 17, 41, 67, 103, 167, 227, 307, 401, 467, 599, 751, 853, 1087, 1279, 1409, 1607, 1879, 2027, 2351, 2671, 2731, 3253, 3433, 3803, 4127, 4517, 4817, 5381, 5813, 6203, 6521, 7247, 7489, 8011, 8761, 8933, 9629, 10273, 10861, 11243, 12301, 12421, 13297
Offset: 1

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Author

N. J. A. Sloane, Nov 16 2004

Keywords

Examples

			Start with
2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97 101 103 ... and delete every second term, giving
2 5 11 17 23 31 41 47 59 67 73 83 97 103 ... and delete every 3rd term, giving
2 5 17 23 41 47 67 73 97 103 ... and delete every 4th term, giving
.... Continue forever and what's left is the sequence.
		

Crossrefs

Programs

  • Maple
    S[1]:={seq(ithprime(i),i=1..2500)}: for n from 2 to 2500 do S[n]:=S[n-1] minus {seq(S[n-1][n*i],i=1..nops(S[n-1])/n)} od: A:=S[2500]; # Emeric Deutsch, Nov 15 2004

Extensions

More terms from Ray Chandler and Emeric Deutsch, Nov 16 2004