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A328571
Primorial base expansion of n converted into its prime product form, but with all nonzero digits replaced by 1's: a(n) = A007947(A276086(n)).
16
1, 2, 3, 6, 3, 6, 5, 10, 15, 30, 15, 30, 5, 10, 15, 30, 15, 30, 5, 10, 15, 30, 15, 30, 5, 10, 15, 30, 15, 30, 7, 14, 21, 42, 21, 42, 35, 70, 105, 210, 105, 210, 35, 70, 105, 210, 105, 210, 35, 70, 105, 210, 105, 210, 35, 70, 105, 210, 105, 210, 7, 14, 21, 42, 21, 42, 35, 70, 105, 210, 105, 210, 35, 70, 105, 210, 105, 210, 35, 70
OFFSET
0,2
FORMULA
a(n) = A007947(A276086(n)).
a(n) = A276086(n) / A328572(n).
a(A276156(n)) = A276086(A276156(n)). [And at no other points the equality holds]
A001221(a(n)) = A267263(n).
a(n) = A083346(A276086(n)). - Antti Karttunen, Feb 28 2021
MATHEMATICA
rad[n_] := Times @@ FactorInteger[n][[All, 1]];
A276086[n0_] := Module[{m = 1, i = 1, n = n0, p}, While[n > 0, p = Prime[i]; m *= p^Mod[n, p]; n = Quotient[n, p]; i++]; m];
a[n_] := rad[A276086[n]];
Table[a[n], {n, 0, 100}] (* Jean-François Alcover, Dec 01 2021, after Antti Karttunen in A276086 *)
PROG
(PARI) A328571(n) = { my(m=1, p=2); while(n, m *= (p^!!(n%p)); n = n\p; p = nextprime(1+p)); (m); };
CROSSREFS
Cf. A276156 (gives the indices where this coincides with A276086).
Sequence in context: A261814 A240965 A084228 * A275733 A245499 A323642
KEYWORD
nonn
AUTHOR
Antti Karttunen, Oct 20 2019
STATUS
approved