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a(n) = lcm(n, tau(n), sigma(n)) where tau(k) is the number of divisors of k (A000005) and sigma(k) is the sum of divisors of k (A000203).
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%I #10 Sep 08 2022 08:46:25

%S 1,6,12,84,30,12,56,120,117,180,132,84,182,168,120,2480,306,234,380,

%T 420,672,396,552,120,2325,1092,1080,168,870,360,992,2016,528,1836,

%U 1680,3276,1406,1140,2184,360,1722,672,1892,924,1170,1656,2256,7440,2793,4650

%N a(n) = lcm(n, tau(n), sigma(n)) where tau(k) is the number of divisors of k (A000005) and sigma(k) is the sum of divisors of k (A000203).

%F a(p) = p *(p + 1) for p = primes (A000040).

%e a(6) = lcm(6, tau(6), sigma(6)) = lcm(6, 4, 12) = 12.

%t a[n_] := LCM @@ {n, DivisorSigma[0, n], DivisorSigma[1, n]}; Array[a, 50] (* _Amiram Eldar_, Nov 03 2020 *)

%o (Magma) [LCM([n, #Divisors(n), &+Divisors(n)]): n in [1..100]]

%o (PARI) a(n) = my(f=factor(n)); lcm([n, sigma(f), numdiv(f)]); \\ _Michel Marcus_, Nov 03 2020

%Y Cf. A000005, A000203.

%Y Cf. A337323 (gcd(n, tau(n), sigma(n))), A324528 (lcm(n, tau(n), pod(n))), A324529 (lcm(n, sigma(n), pod(n))).

%K nonn

%O 1,2

%A _Jaroslav Krizek_, Nov 02 2020