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A284253 a(n) = n / A284252(n). 9
1, 2, 3, 4, 5, 6, 7, 8, 9, 2, 11, 12, 13, 2, 15, 16, 17, 18, 19, 4, 21, 2, 23, 24, 25, 2, 27, 4, 29, 6, 31, 32, 3, 2, 35, 36, 37, 2, 3, 8, 41, 6, 43, 4, 45, 2, 47, 48, 49, 10, 3, 4, 53, 54, 55, 8, 3, 2, 59, 12, 61, 2, 63, 64, 65, 6, 67, 4, 3, 14, 71, 72, 73, 2, 75, 4, 77, 6, 79, 16, 81, 2, 83, 12, 85, 2, 3, 8, 89, 18, 91, 4, 3, 2, 95, 96, 97, 14, 9, 20, 101, 6 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..10001

FORMULA

a(n) = n / A284252(n).

MATHEMATICA

a[n_] := Block[{p = First /@ FactorInteger[n]}, n / SelectFirst[p, # > p[[1]]^2 &, 1]]; Array[a, 120] (* Giovanni Resta, Mar 24 2017 *)

PROG

(Scheme) (define (A284253 n) (/ n (A284252 n)))

(PARI) a(n) = if(n<2, return(1), my(f=factor(n)[, 1]); for(i=2, #f, if(f[i]>f[1]^2, return(f[i]))); return(1));

for(n=1, 151, print1(n/a(n), ", ")) \\ Indranil Ghosh, after David A. Corneth, Mar 24 2017

(Python)

from sympy import primefactors

def a(n):

    pf = primefactors(n)

    if pf: min_pf2 = min(pf)**2

    for i in pf:

        if i > min_pf2: return i

    return 1

print([n//a(n) for n in range(1, 151)]) # Indranil Ghosh, Mar 24 2017

CROSSREFS

Cf. A020639, A284252, A284254, A284255, A284256, A284257, A284258, A284259.

Sequence in context: A122481 A110805 A284255 * A318492 A061499 A178051

Adjacent sequences:  A284250 A284251 A284252 * A284254 A284255 A284256

KEYWORD

nonn

AUTHOR

Antti Karttunen, Mar 24 2017

STATUS

approved

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Last modified July 27 12:10 EDT 2021. Contains 346306 sequences. (Running on oeis4.)