A322319 - OEIS

%I #8 Dec 05 2018 17:23:48

%S 1,3,4,6,6,12,8,12,12,18,12,12,14,24,24,24,18,12,20,18,32,36,24,12,30,

%T 42,36,24,30,72,32,48,48,54,48,12,38,60,56,36,42,96,44,36,24,72,48,24,

%U 56,90,72,42,54,36,72,24,80,90,60,72,62,96,96,96,84,144,68,54,96,144,72,12,74,114,120,60,96,168,80,72

%N a(n) = lcm(A003557(n), A048250(n)).

%H Antti Karttunen, <a href="/A322319/b322319.txt">Table of n, a(n) for n = 1..10000</a>

%H <a href="/index/Lc#lcm">Index entries for sequences related to lcm's</a>

%F a(n) = lcm(A003557(n), A048250(n)).

%F a(n) = A001615(n) / A322318(n).

%t a[n_] := If[n == 1, 1, Module[{f=FactorInteger[n]}, LCM[ Times@@ (First[#] ^(Last[#]-1)& /@  f), Times@@((#+1)& @@@ f)]]]; Array[a, 120] (* _Amiram Eldar_, Dec 05 2018 *)

%o (PARI)

%o A003557(n) = { my(f=factor(n)); for (i=1, #f~, f[i, 2] = f[i, 2]-1); factorback(f); }; \\ From A003557

%o A048250(n) = factorback(apply(p -> p+1, factor(n)[, 1]));

%o A322319(n) = lcm(A048250(n), A003557(n));

%Y Cf. A001615, A003557, A048250, A322318.

%Y Cf. also A322321, A322359.

%K nonn

%O 1,2

%A _Antti Karttunen_, Dec 05 2018