A104355 Number of trailing zeros in decimal representation of A104350(n).

0, 0, 0, 0, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6

Offset: 1

Author

Reinhard Zumkeller, Mar 06 2005

Keywords

• nonn
• base

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000
• David A. Corneth, PARI link
• Reinhard Zumkeller, Products of largest prime factors of numbers <= n.

Crossrefs

Cf. A000079, A027868, A080193, A104350, A104356, A122840.

Programs

Mathematica

IntegerExponent[FoldList[Times, Array[FactorInteger[#][[-1, 1]] &, 100]], 10] (* Amiram Eldar, Apr 08 2024 *)

PARI

gpf(n) = {my(p = factor(n)[, 1]); p[#p];}
a(n) = valuation(prod(k = 2, n, gpf(k)), 10); \\ Amiram Eldar, Apr 08 2024

PARI

\\ See link. David A. Corneth, Apr 08 2024

Formula

a(A104356(n)) = n and a(m) < n for m < A104356(n);

a(n) = A122840(A104350(n)). - Reinhard Zumkeller, Mar 10 2013