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

1,2

COMMENTS

n divides lcm(1, 2, ..., a(n)).

a(n) = A210208(n,A073093(n)) = largest term of n-th 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

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Last modified December 13 09:55 EST 2017. Contains 295957 sequences.