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A111089 Largest prime factor of 2n. 1
2, 2, 3, 2, 5, 3, 7, 2, 3, 5, 11, 3, 13, 7, 5, 2, 17, 3, 19, 5, 7, 11, 23, 3, 5, 13, 3, 7, 29, 5, 31, 2, 11, 17, 7, 3, 37, 19, 13, 5, 41, 7, 43, 11, 5, 23, 47, 3, 7, 5, 17, 13, 53, 3, 11, 7, 19, 29, 59, 5, 61, 31, 7, 2, 13, 11, 67, 17, 23, 7, 71, 3, 73, 37, 5, 19, 11, 13, 79, 5, 3, 41, 83, 7 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

For composite indices we have a(n*m) = max(a(n), a(m)). - Stefan Steinerberger, Nov 13 2005

Same as A006530 except for initial term. - Franklin T. Adams-Watters, Jul 17 2008

LINKS

Table of n, a(n) for n=1..84.

MATHEMATICA

Table[FactorInteger[2n][[ -1, 1]], {n, 100}] (* Ray Chandler *)

CROSSREFS

Bisection of A006530.

Sequence in context: A151663 A162753 A238480 * A051664 A318884 A280990

Adjacent sequences:  A111086 A111087 A111088 * A111090 A111091 A111092

KEYWORD

nonn

AUTHOR

Giovanni Teofilatto, Nov 12 2005

EXTENSIONS

Corrected and extended by Ray Chandler and Stefan Steinerberger, Nov 12 2005

STATUS

approved

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Last modified March 21 12:04 EDT 2019. Contains 321369 sequences. (Running on oeis4.)