

A034699


Largest prime power factor of n.


38



1, 2, 3, 4, 5, 3, 7, 8, 9, 5, 11, 4, 13, 7, 5, 16, 17, 9, 19, 5, 7, 11, 23, 8, 25, 13, 27, 7, 29, 5, 31, 32, 11, 17, 7, 9, 37, 19, 13, 8, 41, 7, 43, 11, 9, 23, 47, 16, 49, 25, 17, 13, 53, 27, 11, 8, 19, 29, 59, 5, 61, 31, 9, 64, 13, 11, 67, 17, 23, 7, 71, 9, 73, 37, 25, 19, 11, 13, 79
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OFFSET

1,2


COMMENTS

n divides lcm(1, 2, ..., a(n)).
a(n) = A210208(n,A073093(n)) = largest term of nth row in A210208.  Reinhard Zumkeller, Mar 18 2012
a(n) = smallest m > 0 such that n divides A003418(m).  Thomas Ordowski, Nov 15 2013
a(n) = n when n is a prime power (A000961).  Michel Marcus, Dec 03 2013


LINKS

T. D. Noe, Table of n, a(n) for n = 1..1000


FORMULA

If n = p_1^e_1 *...* p_k^e_k, p_1<...<p_k primes, then a(n) = max { p_i^e_i }.


MATHEMATICA

f[n_] := If[n == 1, 1, Max[ #[[1]]^#[[2]] & /@ FactorInteger@n]]; Array[f, 79] (* Robert G. Wilson v Sep 02 2006 *)


PROG

(Haskell)
a034699 = last . a210208_row
 Reinhard Zumkeller, Mar 18 2012, Feb 14 2012
(PARI) a(n)=my(f=factor(n)); vecmax(vector(#f[, 1], i, f[i, 1]^f[i, 2])) \\ Charles R Greathouse IV, Nov 20 2012


CROSSREFS

Cf. A020639, A006530, A034684, A028233, A034699, A053585, A051283, A052128, A038610, A027750, A010055.
Sequence in context: A053585 A098988 A274346 * A217434 A295126 A235602
Adjacent sequences: A034696 A034697 A034698 * A034700 A034701 A034702


KEYWORD

nonn,easy,nice


AUTHOR

David W. Wilson


STATUS

approved



