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A069934
a(n) = lcm_{d|n} sigma(d).
11
1, 3, 4, 21, 6, 12, 8, 105, 52, 18, 12, 84, 14, 24, 24, 3255, 18, 156, 20, 126, 32, 36, 24, 420, 186, 42, 520, 168, 30, 72, 32, 9765, 48, 54, 48, 1092, 38, 60, 56, 630, 42, 96, 44, 252, 312, 72, 48, 13020, 456, 558, 72, 294, 54, 1560, 72, 840, 80, 90, 60, 504, 62, 96
OFFSET
1,2
FORMULA
Multiplicative with a(p^e) = Product_{k=2..e+1} Phi_k(p), where Phi_k(x) is k-th cyclotomic polynomial.
MATHEMATICA
Table[LCM@@(DivisorSigma[1, #]&/@Divisors[n]), {n, 70}] (* Harvey P. Dale, Feb 22 2023 *)
PROG
(PARI) A069934(n) = my(d = divisors(n)); lcm(vector(#d, k, sigma(d[k]))); \\ Antti Karttunen, Sep 10 2017
CROSSREFS
KEYWORD
mult,nonn
AUTHOR
Vladeta Jovovic, Apr 25 2002
STATUS
approved