A274771 Number of primes <= n-th Carmichael lambda number.

0, 0, 1, 1, 2, 1, 3, 1, 3, 2, 4, 1, 5, 3, 2, 2, 6, 3, 7, 2, 3, 4, 8, 1, 8, 5, 7, 3, 9, 2, 10, 4, 4, 6, 5, 3, 11, 7, 5, 2, 12, 3, 13, 4, 5, 8, 14, 2, 13, 8, 6, 5, 15, 7, 8, 3, 7, 9, 16, 2, 17, 10, 3, 6, 5, 4, 18, 6, 8, 5, 19, 3, 20, 11, 8, 7, 10, 5, 21, 2

Offset

1,5

Links

Table of n, a(n) for n=1..80.

Formula

a(n) = A000720(A002322(n)). - Michel Marcus, Nov 11 2016

Maple

with(numtheory):
a:= n-> pi(lambda(n)):
seq(a(n), n=1..100);  # Alois P. Heinz, Nov 11 2016

Mathematica

Table[PrimePi[CarmichaelLambda[n]], {n, 100}]

Prog

(Magma) [0] cat [#PrimesUpTo(CarmichaelLambda(n)): n in [2..100]];

Crossrefs

Cf. A002322, A054782, A070804, A273974, A277062, A277063.

Sequence in context: A309633 A329632 A014599 * A075825 A309155 A007735

Adjacent sequences: A274768 A274769 A274770 * A274772 A274773 A274774

Keyword

nonn

Author

Vincenzo Librandi, Nov 11 2016

Status

approved