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A077063 Squarefree kernel of prime(n) - 1. 6
1, 2, 2, 6, 10, 6, 2, 6, 22, 14, 30, 6, 10, 42, 46, 26, 58, 30, 66, 70, 6, 78, 82, 22, 6, 10, 102, 106, 6, 14, 42, 130, 34, 138, 74, 30, 78, 6, 166, 86, 178, 30, 190, 6, 14, 66, 210, 222, 226, 114, 58, 238, 30, 10, 2, 262, 134, 30, 138, 70, 282, 146, 102, 310, 78, 158 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
FORMULA
a(n) = A007947(A006093(n)).
EXAMPLE
a(25) = rad(prime(25)-1) = rad(97-1) = rad(3*2^5) = 6.
MAPLE
A077063 := proc(n)
end proc:
seq(A077063(n), n=1..30) ; # R. J. Mathar, Jan 13 2021
MATHEMATICA
rad[n_] := Times @@ (First@# & /@ FactorInteger[n]); rad /@
Select[Range[400], PrimeQ[# + 1] &] (* Amiram Eldar, Dec 29 2020 *)
Times@@FactorInteger[#-1][[;; , 1]]&/@Prime[Range[70]] (* Harvey P. Dale, Mar 16 2023 *)
PROG
(PARI) a(n)=my(f=factor(prime(n)-1)[, 1]); prod(i=1, #f, f[i]) \\ Charles R Greathouse IV, Aug 21 2013
(Haskell)
a077063 = a007947 . a006093 -- Reinhard Zumkeller, Sep 04 2013
CROSSREFS
Sequence in context: A327485 A207975 A321623 * A081728 A197218 A080460
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Oct 23 2002
EXTENSIONS
Wrong formula removed by Amiram Eldar, Dec 29 2020
STATUS
approved

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Last modified April 22 02:54 EDT 2024. Contains 371887 sequences. (Running on oeis4.)