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A118500 A variation on Flavius's sieves (A000960, A099207): Start with Chen 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. 0
2, 5, 17, 41, 83, 137, 233, 317, 467, 617, 761, 941, 1259, 1427, 1913, 2281, 2531, 2957, 3511, 3797, 4447, 5153, 5351, 6481, 6863, 7669, 8581, 9533, 10259, 11497, 12569, 13441, 14081, 15737, 16187, 17657, 19541, 19991, 21587, 23017, 24317 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

LINKS

Table of n, a(n) for n=0..40.

EXAMPLE

Start with

2 3 5 7 11 13 17 19 23 29 31 37 41 47 53 59 67 71 83 89 101 107 109 113 127 131 ... and delete every second term, giving

2 5 11 17 23 31 41 53 67 83 101 109 127 ... and delete every 3rd term, giving

2 5 17 23 41 53 83 101 127 ... and delete every 4th term, giving

.... Continue forever and what's left is the sequence.

MAPLE

ts_chen:= proc(n) local i, ans; ans:=[ ]: for i from 1 to n do if ( isprime(i) = 'true') then if ( isprime(i+2) = 'true' or numtheory[bigomega](i+2) = 2) then ans:=[ op(ans), i ] fi fi od: return ans end: S[1]:=convert(ts_chen(25000), set): 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: convert(S[2100], list);

CROSSREFS

Cf. A000960, A099207, A109611.

Sequence in context: A197918 A122566 A263638 * A323427 A080898 A081763

Adjacent sequences:  A118497 A118498 A118499 * A118501 A118502 A118503

KEYWORD

nonn

AUTHOR

Jani Melik, May 05 2006

STATUS

approved

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Last modified October 21 08:47 EDT 2019. Contains 328292 sequences. (Running on oeis4.)