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 A103228 Real part of the sum of divisors function sigma(n) generalized for Gaussian integers. 18
 1, 2, 4, -4, 4, 8, 8, -8, 13, -16, 12, -16, 6, 16, 16, 16, 6, 26, 20, -56, 32, 24, 24, -32, -36, -42, 40, -32, 8, -64, 32, 32, 48, -54, 32, -52, 8, 40, 24, 24, 10, 64, 44, -48, 52, 48, 48, 64, 57, -165, 24, -114, 10, 80, 48, -64, 80, -92, 60, -224, 12, 64, 104, -64, -120, 96, 68, -134, 96, -128, 72, -104, 12, -116, -144, -80, 96 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS See A103229 for the imaginary part and A103230 for the norm. See A102506 for a complete description. Note that sigma(n) is real iff n is in A004614. LINKS Amiram Eldar, Table of n, a(n) for n = 1..10000 MATHEMATICA Re[Table[DivisorSigma[1, n, GaussianIntegers -> True], {n, 100}]] CROSSREFS Cf. A004614, A102506, A103229, A103230. Sequence in context: A117726 A172307 A108039 * A076340 A076345 A327331 Adjacent sequences: A103225 A103226 A103227 * A103229 A103230 A103231 KEYWORD sign AUTHOR T. D. Noe, Jan 26 2005 STATUS approved

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Last modified February 5 12:47 EST 2023. Contains 360084 sequences. (Running on oeis4.)