OFFSET
1,1
COMMENTS
a(n)-1 is the number of factorials below the n-th primorial.
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
EXAMPLE
For n = 26: a(26) = 34 since there are 33 factorials below the 26th primorial.
MATHEMATICA
fn[n_] := Module[{k = 1, r = n}, While[r >= 1, k++; r /= k]; k - 1]; prim[n_] := Times @@ Prime[Range[n]]; a[1] = 2; a[n_] := fn[prim[n]] + 1; Array[a, 100] (* Amiram Eldar, Feb 09 2025 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Labos Elemer, Jun 26 2003
EXTENSIONS
Name edited by Sean A. Irvine, Jun 13 2026
STATUS
approved