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A340679
If n is a power of prime then a(n) = 1, otherwise a(n) = product of the distinct prime factors of n.
1
1, 1, 1, 1, 1, 6, 1, 1, 1, 10, 1, 6, 1, 14, 15, 1, 1, 6, 1, 10, 21, 22, 1, 6, 1, 26, 1, 14, 1, 30, 1, 1, 33, 34, 35, 6, 1, 38, 39, 10, 1, 42, 1, 22, 15, 46, 1, 6, 1, 10, 51, 26, 1, 6, 55, 14, 57, 58, 1, 30, 1, 62, 21, 1, 65, 66, 1, 34, 69, 70, 1, 6, 1, 74, 15, 38, 77, 78, 1, 10, 1, 82, 1, 42, 85, 86, 87, 22, 1, 30, 91, 46
OFFSET
1,6
FORMULA
If A010055(n) == 1 [when n is a power of prime], a(n) = 1, otherwise a(n) = A007947(n).
a(n) = A007947(n) / A014963(n).
MATHEMATICA
Table[If[PrimePowerQ[n], 1, Times@@FactorInteger[n][[All, 1]]], {n, 100}] (* Harvey P. Dale, May 23 2021 *)
PROG
(PARI) A340679(n) = if(isprimepower(n), 1, factorback(factorint(n)[, 1]));
CROSSREFS
Cf. A000961 (positions of ones), A007947, A010055, A014963.
Cf. also A048671, A322591.
Sequence in context: A348979 A080304 A340677 * A166142 A290479 A304404
KEYWORD
nonn
AUTHOR
Antti Karttunen, Feb 01 2021
STATUS
approved