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A066332 a(1)=1; for n > 0, a(n+1) = rad(a(n))*n where rad=A007947.

%I A066332 #40 Jun 12 2022 06:42:19
%S A066332 1,1,2,6,24,30,180,210,1680,1890,2100,2310,27720,30030,420420,450450,
%T A066332 480480,510510,9189180,9699690,193993800,203693490,213393180,
%U A066332 223092870,5354228880,5577321750,5800414620,6023507490,6246600360,6469693230,194090796900,200560490130
%N A066332 a(1)=1; for n > 0, a(n+1) = rad(a(n))*n where rad=A007947.
%F A066332 a(1)=1; for n > 1, a(n) = (n-1) * Product_{p prime < (n-1)} p. - _Pedro Caceres_, Mar 12 2018
%F A066332 a(A008864(n)) = A002110(n). - _Michel Marcus_, Mar 17 2018
%t A066332 rad[n_] := Times @@ (First@# & /@ FactorInteger@n); a[n_] := (n -1)rad[a[n -1]]; a[1] = 1; Array[a, 30] (* _Robert G. Wilson v_, Dec 14 2016 and modified Dec 24 2016 *)
%o A066332 (PARI) a(n) = if(n==1, 1, (n-1)*prod(k=1, primepi(n-2), prime(k))); \\ _Daniel Suteu_, Dec 14 2016
%o A066332 (PARI) rad(n) = factorback(factorint(n)[, 1]);
%o A066332 a(n) = if (n==1, 1, (n-1)*rad(a(n-1))); \\ _Michel Marcus_, Dec 21 2016
%Y A066332 Cf. A002110, A008864, A049614.
%K A066332 nonn
%O A066332 1,3
%A A066332 _Reinhard Zumkeller_, Jan 05 2002
%E A066332 More terms from _Michel Marcus_, Mar 17 2018