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 A319296 a(n) = (Sum_{d|n} (sigma(d))) mod sigma(n). 4
 0, 1, 1, 4, 1, 8, 1, 11, 5, 10, 1, 27, 1, 12, 11, 26, 1, 33, 1, 35, 13, 16, 1, 10, 7, 18, 18, 43, 1, 68, 1, 57, 17, 22, 15, 16, 1, 24, 19, 2, 1, 84, 1, 59, 48, 28, 1, 37, 9, 59, 23, 67, 1, 112, 19, 114, 25, 34, 1, 49, 1, 36, 58, 120, 21, 116, 1, 83, 29, 108 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,4 COMMENTS a(n) = A007429(n) mod A000203(n). LINKS Antti Karttunen, Table of n, a(n) for n = 1..65537 FORMULA a(A221219(n)) = 0. a(A000040(n)) = 1; the only composite number < 2*10^6 with a(n) = 1 is 636. a(n) = n only for numbers 4, 10 and 96 < 3000000. EXAMPLE For n = 4; a(4) = ((sigma(1) + sigma(2) + sigma(4)) mod sigma(4) = (1+3+7) mod 7 = 11 mod 7 = 4. MATHEMATICA Table[Mod[Sum[DivisorSigma[1, d], {d, Divisors[n]}], DivisorSigma[1, n]], {n, 1, 100}] (* Vaclav Kotesovec, Sep 26 2018 *) PROG (MAGMA) [&+[SumOfDivisors(d): d in Divisors(n)] mod  SumOfDivisors(n): n in [1..1000]] (PARI) A319296(n) = (sumdiv(n, d, sigma(d))%sigma(n)); \\ Antti Karttunen, Sep 16 2018 CROSSREFS Cf. A000203, A007429, A221219. Sequence in context: A040019 A240776 A019768 * A211779 A318445 A158496 Adjacent sequences:  A319293 A319294 A319295 * A319297 A319298 A319299 KEYWORD nonn AUTHOR Jaroslav Krizek, Sep 16 2018 STATUS approved

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Last modified April 20 03:02 EDT 2021. Contains 343121 sequences. (Running on oeis4.)