A104351 Number of digits in decimal representation of A104350(n).

1, 1, 1, 2, 2, 3, 4, 4, 4, 5, 6, 7, 8, 9, 9, 10, 11, 11, 13, 13, 14, 15, 16, 17, 18, 19, 19, 20, 22, 22, 24, 24, 25, 26, 27, 28, 29, 30, 32, 32, 34, 35, 36, 37, 38, 40, 41, 42, 42, 43, 44, 46, 47, 48, 49, 50, 51, 52, 54, 55, 57, 58, 59, 59, 60, 61, 63, 64, 66, 67, 69, 69, 71, 72

Offset: 1

Author

Reinhard Zumkeller, Mar 06 2005

Keywords

• nonn
• base

Links

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

Crossrefs

Cf. A034886, A055642, A104350.

Programs

Mathematica

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

PARI

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

Formula

a(n) = A055642(A104350(n)).