OFFSET
1,2
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
KEYWORD
nonn,more
AUTHOR
Andres Cicuttin, Sep 29 2016
EXTENSIONS
Definition aligned with formulas and data by Peter Munn, Sep 06 2023
STATUS
approved