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 A332478 Number that are unitary norm-multiply-perfect numbers in Gaussian integers. 0
 1, 10, 12, 20160, 15713280, 137592000, 44289146880 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Numbers k such that their norm of sum of unitary divisors in Gaussian integers, A332474(k), is divisible by their norm, k^2. The corresponding ratios A332474(a(n))/(a(n)^2) are 1, 4, 1, 5, 5, 2, 5. LINKS EXAMPLE 10 is a term since its sum of unitary divisors in Gaussian integers is -12 + 16*i, whose norm (-12)^2 + 16^2 = 400 is divisible by 10^2 = 100. MATHEMATICA f[p_, e_] := If[Abs[p] == 1, 1, (p^e + 1)]; Select[Range[21000], Divisible[Abs[ Times @@ f @@@ FactorInteger[#, GaussianIntegers -> True]]^2, #^2] &] CROSSREFS Cf. A002827, A327158, A332318, A332319, A332474. Sequence in context: A255534 A262422 A248336 * A144814 A241174 A092887 Adjacent sequences: A332475 A332476 A332477 * A332479 A332480 A332481 KEYWORD nonn,more AUTHOR Amiram Eldar, Feb 13 2020 STATUS approved

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Last modified March 25 09:47 EDT 2023. Contains 361520 sequences. (Running on oeis4.)