A268336 - OEIS

%I #31 Sep 08 2022 08:46:15

%S 1,1,2,1,4,1,6,1,2,2,10,1,12,3,4,1,16,1,18,1,2,5,22,1,4,6,2,3,28,2,30,

%T 1,10,8,12,1,36,9,4,1,40,1,42,5,4,11,46,1,6,2,16,3,52,1,4,3,6,14,58,1,

%U 60,15,2,1,12,5,66,4,22,6,70,1,72,18,4,9,30,2,78,1,2

%N a(n) = A174824(n)/n, where A174824(n) = lcm(A002322(n), n) and A002322(n) is the Carmichael lambda function (also known as the reduced totient function or the universal exponent of n).

%F a(n) = A174824(n)/n.

%F a(A124240(n)) = 1. - _Michel Marcus_, Feb 21 2016

%t Table[LCM[n, CarmichaelLambda@ n]/n, {n, 100}] (* _Michael De Vlieger_, Feb 03 2016, after _T. D. Noe_ at A174824 *)

%o (Magma) [1] cat [Lcm(n, CarmichaelLambda(n))/n: n in [2..100]]: // Feb 03 2016

%o (PARI) a(n)=my(ps); ps=factor(n)[, 1]~; m = n; for(k=1, #ps, m=lcm(m, ps[k]-1)); m/n \\ _Michel Marcus_, Feb 21 2016

%o (PARI) apply( {A268336(n)=lcm(lcm([p-1|p<-factor(n)[,1]]),n)/n}, [1..99]) \\ [...] = znstar(n)[2], but 3x faster. - _M. F. Hasler_, Nov 13 2019

%Y Cf. A002322, A068563, A124240, A174824.

%K nonn,easy

%O 1,3

%A _Juri-Stepan Gerasimov_, Feb 01 2016

%E More terms from _Vincenzo Librandi_, Feb 03 2016