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A258568
Smallest prime factors of 3-full numbers.
6
1, 2, 2, 3, 2, 2, 3, 5, 2, 2, 3, 2, 7, 2, 2, 5, 2, 3, 2, 2, 2, 2, 11, 2, 2, 2, 2, 3, 13, 7, 2, 2, 5, 3, 2, 2, 2, 2, 17, 2, 2, 2, 2, 3, 19, 2, 2, 2, 2, 3, 2, 3, 2, 2, 2, 2, 23, 2, 11, 2, 5, 2, 2, 7, 3, 2, 2, 2, 3, 2, 2, 2, 2, 2, 29, 2, 2, 2, 3, 13, 31, 3, 2, 2
OFFSET
1,2
LINKS
Reinhard Zumkeller, Table of n, a(n) for n = 1..10000 (corrected by Amiram Eldar)
FORMULA
a(n) = A020639(A036966(n)).
a(A258600(n)) = A000040(n) and a(m) != A000040(n) for m < A258600(n).
MATHEMATICA
Table[If[Min[(f = FactorInteger[n])[[;; , 2]]] > 2 || n == 1, f[[1, 1]], Nothing], {n, 1, 30000}] (* Amiram Eldar, Feb 07 2023 *)
PROG
(Haskell)
a258568 = a020639 . a036966
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Jun 06 2015
EXTENSIONS
Missing term a(78) inserted by Amiram Eldar, Feb 07 2023
STATUS
approved