OFFSET
0,4
LINKS
Soumyadeep Dhar, Table of n, a(n) for n = 0..5000
MAPLE
with(numtheory): it := 1: for n from 1 to 150 do it := it*ithprime(n): printf(`%d, `, ceil(log[10](it))) od:
MATHEMATICA
Table[Floor[Log[10, Product[Prime[k], {k, n}]] + 1], {n, 0, 67}]
Join[{1}, IntegerLength/@FoldList[Times, Prime[Range[70]]]] (* Harvey P. Dale, Jan 03 2024 *)
PROG
(PARI) a(n) = 1 + logint(vecprod(primes(n)), 10) \\ Andrew Howroyd, Apr 24 2021
(Python)
from sympy import primorial
def a(n): return 1 if n == 0 else len(str(primorial(n)))
print([a(n) for n in range(68)]) # Michael S. Branicky, Apr 24 2021
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Lekraj Beedassy, Feb 18 2002
EXTENSIONS
Edited and extended by Robert G. Wilson v and James A. Sellers, Feb 19 2002
Offset corrected by Arkadiusz Wesolowski, May 04 2013
STATUS
approved