A104351 - OEIS

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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

(list; graph; refs; listen; history; text; internal format)

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]; }