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A077063 Squarefree kernel of prime(n) - 1.

%I A077063 #19 Mar 16 2023 15:16:10
%S A077063 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,
%T A077063 102,106,6,14,42,130,34,138,74,30,78,6,166,86,178,30,190,6,14,66,210,
%U A077063 222,226,114,58,238,30,10,2,262,134,30,138,70,282,146,102,310,78,158
%N A077063 Squarefree kernel of prime(n) - 1.
%H A077063 Reinhard Zumkeller, <a href="/A077063/b077063.txt">Table of n, a(n) for n = 1..10000</a>
%F A077063 a(n) = A007947(A006093(n)).
%e A077063 a(25) = rad(prime(25)-1) = rad(97-1) = rad(3*2^5) = 6.
%p A077063 A077063 := proc(n)
%p A077063     A007947(A006093(n)) ;
%p A077063 end proc:
%p A077063 seq(A077063(n),n=1..30) ; # _R. J. Mathar_, Jan 13 2021
%t A077063 rad[n_] := Times @@ (First@# & /@ FactorInteger[n]); rad /@
%t A077063 Select[Range[400], PrimeQ[# + 1] &] (* _Amiram Eldar_, Dec 29 2020 *)
%t A077063 Times@@FactorInteger[#-1][[;;,1]]&/@Prime[Range[70]] (* _Harvey P. Dale_, Mar 16 2023 *)
%o A077063 (PARI) a(n)=my(f=factor(prime(n)-1)[,1]); prod(i=1,#f,f[i]) \\ _Charles R Greathouse IV_, Aug 21 2013
%o A077063 (Haskell)
%o A077063 a077063 = a007947 . a006093  -- _Reinhard Zumkeller_, Sep 04 2013
%Y A077063 Cf. A006093, A007947, A077066.
%K A077063 nonn
%O A077063 1,2
%A A077063 _Reinhard Zumkeller_, Oct 23 2002
%E A077063 Wrong formula removed by _Amiram Eldar_, Dec 29 2020