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A152021
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Numbers a(n) are obtained by the direct application of sieve of Eratosthenes for A000695: retaining A000695(2)=4, we delete all multiples of 4, which are more than 4; retaining A000695(3)=5, we delete all multiples of 5, which are more than 5, etc.
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8
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4, 5, 17, 21, 69, 81, 257, 261, 277, 321, 337, 341, 1041, 1089, 1093, 1109, 1297, 1301, 1349, 1361, 4101, 4113, 4117, 4161, 4177, 4181, 4353, 4357, 4373, 4417, 4421, 5121, 5137, 5141, 5189, 5201, 5377, 5381, 5393
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| If p is prime, then A000695(p) is in the sequence; but, e. g., A000695(25), A000695(55) are also in the sequence.
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MAPLE
| Contribution from R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Oct 29 2010: (Start)
A000695 := proc(n) local dgsa ; if n= 0 then 0; else for a from procname(n-1)+1 do dgsa := convert(convert(a, base, 4), set) ; if dgsa minus {0, 1} = {} then return a; end if; end do: end if; end proc:
A152021 := proc(nmax) a := [seq(A000695(i), i=2..nmax)] ; ptr := 1; while ptr < nops(a) do for j from nops(a) to ptr+1 by -1 do if op(j, a) mod op(ptr, a) = 0 then a := subsop(j=NULL, a) ; end if; end do: ptr := ptr+1 ; end do: a ; end proc: A152021(120) ; (End)
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CROSSREFS
| A000695
Sequence in context: A032049 A045680 A174352 * A026678 A026869 A061806
Adjacent sequences: A152018 A152019 A152020 * A152022 A152023 A152024
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KEYWORD
| nonn
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AUTHOR
| Vladimir Shevelev (shevelev(AT)bgu.ac.il), Nov 20 2008
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EXTENSIONS
| More terms from R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Oct 29 2010
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