A087267 a(n) = gcd(n, pi(n)) where pi is A000720.

1, 1, 1, 2, 1, 3, 1, 4, 1, 2, 1, 1, 1, 2, 3, 2, 1, 1, 1, 4, 1, 2, 1, 3, 1, 1, 9, 1, 1, 10, 1, 1, 11, 1, 1, 1, 1, 2, 3, 4, 1, 1, 1, 2, 1, 2, 1, 3, 1, 5, 3, 1, 1, 2, 1, 8, 1, 2, 1, 1, 1, 2, 9, 2, 1, 6, 1, 1, 1, 1, 1, 4, 1, 1, 3, 1, 7, 3, 1, 2, 1, 2, 1, 1, 1, 1, 1, 1, 1, 6, 1, 4, 3, 2, 1, 24, 1, 1, 1, 25, 1, 2, 1

Offset

1,4

Links

Ivan Neretin, Table of n, a(n) for n = 1..10000

Mathematica

Table[GCD[w, PrimePi[w]], {w, 1, 256}]

Prog

(PARI) a(n) = gcd(n, primepi(n)); \\ Michel Marcus, Apr 22 2018

Crossrefs

Cf. A007053, A000720, A087266, A057809.

Sequence in context: A305556 A177812 A280504 * A128267 A289508 A364448

Adjacent sequences: A087264 A087265 A087266 * A087268 A087269 A087270

Keyword

nonn

Author

Labos Elemer, Sep 16 2003

Status

approved