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 A354205 a(n) = sigma(A354202(n)), where A354202 is fully multiplicative with a(p) = A354200(A000720(p)). 5
 1, 6, 8, 31, 14, 48, 12, 156, 57, 84, 20, 248, 18, 72, 112, 781, 30, 342, 24, 434, 96, 120, 32, 1248, 183, 108, 400, 372, 38, 672, 44, 3906, 160, 180, 168, 1767, 42, 144, 144, 2184, 54, 576, 48, 620, 798, 192, 60, 6248, 133, 1098, 240, 558, 62, 2400, 280, 1872, 192, 228, 68, 3472, 74, 264, 684, 19531, 252, 960, 72 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Table of n, a(n) for n=1..67. Index entries for sequences computed from indices in prime factorization Index entries for sequences related to sigma(n) FORMULA Multiplicative with a(p^e) = (q^(e+1)-1)/(q-1) where q = A354200(A000720(p)). a(n) = A000203(A354202(n)). a(n) = Sum_{d|n} A354202(d). PROG (PARI) A354200(n) = if(1==n, 5, my(p=prime(n), m=p%4); forprime(q=1+p, , if(m==(q%4), return(q)))); A354205(n) = { my(f=factor(n)); for(k=1, #f~, f[k, 1] = A354200(primepi(f[k, 1]))); sigma(factorback(f)); }; \\ Alternatively: A354205(n) = sumdiv(n, d, A354202(d)); CROSSREFS Cf. A000203, A000290 (positions of odd terms), A000720, A354200, A354202, A354204, A354206. Cf. A003973, A354089, A354093 for variants. Sequence in context: A323201 A261062 A076904 * A219681 A025091 A356742 Adjacent sequences: A354202 A354203 A354204 * A354206 A354207 A354208 KEYWORD nonn,mult AUTHOR Antti Karttunen, May 23 2022 STATUS approved

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Last modified June 7 11:55 EDT 2023. Contains 363157 sequences. (Running on oeis4.)