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A279984 Positions of the prime numbers in the sequence of numbers that are not perfect powers (A007916). 2
1, 2, 3, 5, 7, 9, 12, 14, 18, 22, 24, 28, 32, 34, 38, 43, 49, 51, 56, 60, 62, 68, 71, 77, 85, 88, 90, 94, 96, 100, 112, 115, 121, 123, 132, 134, 140, 146, 150, 155, 161, 163, 173, 175, 178, 180, 192, 203, 206, 208, 212, 218, 220, 229, 234, 240, 246, 248, 254 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

John Cerkan, Table of n, a(n) for n = 1..10000

FORMULA

A007916(a(n)) = A000040(n).

MATHEMATICA

nn=100; rads=Select[Range[2, nn], GCD@@FactorInteger[#][[All, 2]]===1&];

Table[Position[rads, Prime[n]][[1, 1]], {n, PrimePi[nn]}]

PROG

(PARI) lista(nn) = Vec(select(x->isprime(x), Vec(select(x->(!ispower(x)&&x>1), [1..nn])), 1)); \\ Michel Marcus, May 04 2018

CROSSREFS

Cf. A000040, A007916, A279944.

Sequence in context: A284914 A293262 A200049 * A184017 A024195 A071423

Adjacent sequences:  A279981 A279982 A279983 * A279985 A279986 A279987

KEYWORD

nonn

AUTHOR

Gus Wiseman, Dec 24 2016

STATUS

approved

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Last modified November 21 06:00 EST 2019. Contains 329350 sequences. (Running on oeis4.)