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A144570
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Nonprime(prime(n)).
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4
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1, 4, 8, 10, 16, 20, 25, 27, 33, 40, 44, 51, 56, 58, 64, 72, 80, 82, 90, 94, 96, 105, 111, 118, 126, 132, 134, 140, 142, 146, 164, 169, 176, 178, 190, 194, 202, 208, 213, 219, 226, 230, 243, 245, 249, 252, 266, 282, 287, 289, 294, 300, 302, 315, 322, 328, 335
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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COMMENTS
| The nonprimes A141468 at prime indices. [From Juri-Stepan Gerasimov, Jul 22 2011]
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FORMULA
| a(n)=A141468(A000040(n)).
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EXAMPLE
| If n=1, then a(1)=nonprime(prime(1))=nonprime(2)=1. If n=2, then a(2)=nonprime(prime(2))=nonprime( 3)=4. If n=3, then a(3)=nonprime(prime(3))=nonprime(5)=8, etc.
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MAPLE
| A141468 := proc(n) option remember ; if n <= 2 then n-1 ; else for a from procname(n-1)+1 do if not isprime(a) then return a; end if; end do: end if; end proc: A144570 := proc(n) A141468(ithprime(n)) ; end proc: seq(A144570(n), n=1..100) ; [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Mar 18 2010]
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CROSSREFS
| Cf. A000040, A141468.
Sequence in context: A153975 A020169 A082934 * A036311 A020209 A046559
Adjacent sequences: A144567 A144568 A144569 * A144571 A144572 A144573
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KEYWORD
| nonn
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AUTHOR
| Juri-Stepan Gerasimov (2stepan(AT)rambler.ru), Jan 07 2009
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