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

1,4

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Reinhard Zumkeller, Products of largest prime factors of numbers <= n.

Formula

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

Mathematica

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

Prog

(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

Crossrefs

Cf. A034886, A055642, A104350.

Sequence in context: A078881 A336095 A131807 * A366274 A284511 A262976

Adjacent sequences: A104348 A104349 A104350 * A104352 A104353 A104354

Keyword

nonn,base

Author

Reinhard Zumkeller, Mar 06 2005

Status

approved