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A064988
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Multiplicative with a(p^e) = prime(p)^e.
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28
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1, 3, 5, 9, 11, 15, 17, 27, 25, 33, 31, 45, 41, 51, 55, 81, 59, 75, 67, 99, 85, 93, 83, 135, 121, 123, 125, 153, 109, 165, 127, 243, 155, 177, 187, 225, 157, 201, 205, 297, 179, 255, 191, 279, 275, 249, 211, 405, 289, 363, 295, 369, 241, 375, 341, 459, 335, 327
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OFFSET
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1,2
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LINKS
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FORMULA
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For n = p_{i1} * p_{i2} * ... * p_{ik}, where the indices i1, i2, ..., ik of primes p are not necessarily distinct, a(n) = A006450(i1) * A006450(i2) * ... * A006450(ik).
(End)
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EXAMPLE
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a(12) = a(2^2*3) = prime(2)^2 * prime(3) = 3^2*5 = 45, where prime(n) = A000040(n).
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MAPLE
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a:= n-> mul(ithprime(i[1])^i[2], i=ifactors(n)[2]):
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MATHEMATICA
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Table[If[n == 1, 1, Apply[Times, FactorInteger[n] /. {p_, e_} /; p > 1 :> Prime[p]^e]], {n, 58}] (* Michael De Vlieger, Aug 22 2017 *)
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PROG
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(PARI) { for (n=1, 1000, f=factor(n)~; a=1; for (i=1, length(f), a*=prime(f[1, i])^f[2, i]); write("b064988.txt", n, " ", a) ) } \\ Harry J. Smith, Oct 02 2009
(PARI) a(n) = {my(f = factor(n)); for (k=1, #f~, f[k, 1] = prime(f[k, 1]); ); factorback(f); } \\ Michel Marcus, Aug 08 2017
(Python)
from sympy import factorint, prime
from operator import mul
def a(n): return 1 if n==1 else reduce(mul, [prime(p)**e for p, e in factorint(n).items()])
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CROSSREFS
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Cf. A076610 (terms sorted into ascending order).
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KEYWORD
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mult,nonn
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AUTHOR
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STATUS
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approved
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