A276497 Number of noncomposites in the reduced residue system of n-th primorial number, A002110(n).

1, 2, 8, 43, 339, 3243, 42325, 646022, 12283523, 300369787, 8028643000, 25948875073, 9414916809083, 362597750396727, 15397728527812844, 742238179058722876, 40068968501510691878

Offset

1,2

Links

Table of n, a(n) for n=1..17.

Formula

a(n) = pi(primorial(n)) - n + 1, n > 0.

a(n) = A000849(n) - n + 1, n > 0.

a(n) = A048862(n) + 1. - Michel Marcus, Oct 03 2016

Mathematica

Primorial[n_] := Product[Prime[j], {j, 1, n}];
Table[PrimePi[Primorial[n]] - n + 1, {n, 1, 12}]

Prog

(PARI) a(n) = primepi(prod(k=1, n, prime(k))) - n + 1; \\ Michel Marcus, Oct 03 2016

Crossrefs

Cf. A000849, A002110, A048862.

Sequence in context: A007169 A106327 A009309 * A324670 A334335 A283416

Adjacent sequences: A276494 A276495 A276496 * A276498 A276499 A276500

Keyword

nonn,more

Author

Andres Cicuttin, Sep 29 2016

Extensions

Definition aligned with formulas and data by Peter Munn, Sep 06 2023

Status

approved