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a(n) = lcm(sigma(n), A003961(n)), where A003961 is fully multiplicative with a(prime(k)) = prime(k+1), and sigma is the sum of divisors of n.
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%I #9 Mar 23 2021 16:17:13

%S 1,3,20,63,42,60,88,135,325,126,156,1260,238,264,840,2511,342,975,460,

%T 126,1760,468,696,540,1519,714,1000,5544,930,2520,1184,1701,3120,1026,

%U 3696,20475,1558,1380,4760,1890,1806,5280,2068,3276,13650,2088,2544,50220,6897,4557,6840,14994,3186,3000,6552,11880,1840,2790

%N a(n) = lcm(sigma(n), A003961(n)), where A003961 is fully multiplicative with a(prime(k)) = prime(k+1), and sigma is the sum of divisors of n.

%H Antti Karttunen, <a href="/A342672/b342672.txt">Table of n, a(n) for n = 1..8192</a>

%H <a href="/index/Pri#prime_indices">Index entries for sequences computed from indices in prime factorization</a>

%H <a href="/index/Si#SIGMAN">Index entries for sequences related to sigma(n)</a>

%F a(n) = lcm(A000203(n), A003961(n)).

%F a(n) = A341529(n) / A342671(n).

%o (PARI)

%o A003961(n) = { my(f = factor(n)); for (i=1, #f~, f[i, 1] = nextprime(f[i, 1]+1)); factorback(f); };

%o A342672(n) = lcm(sigma(n), A003961(n));

%Y Cf. A000203, A003961, A341529, A342671.

%K nonn

%O 1,2

%A _Antti Karttunen_, Mar 20 2021