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 A058268 An approximation to sigma_{1/2}(n): ceiling( sum_{d|n} sqrt(d) ). 1
 1, 3, 3, 5, 4, 7, 4, 8, 6, 8, 5, 13, 5, 9, 9, 12, 6, 14, 6, 15, 10, 11, 6, 20, 9, 12, 11, 17, 7, 22, 7, 17, 12, 13, 12, 26, 8, 13, 13, 24, 8, 25, 8, 20, 19, 14, 8, 31, 11, 20, 14, 21, 9, 27, 14, 27, 15, 16, 9, 40, 9, 16, 21, 25, 15, 29, 10, 23, 16, 29, 10, 42 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS MAPLE with(numtheory); f := proc(n) local d, t1, t2; t2 := 0; t1 := divisors(n); for d in t1 do t2 := t2 + sqrt(d) end do; t2 end proc; # exact value of sigma_{1/2}(n) CROSSREFS Sequence in context: A090104 A333822 A075795 * A341729 A087851 A332932 Adjacent sequences:  A058265 A058266 A058267 * A058269 A058270 A058271 KEYWORD nonn AUTHOR N. J. A. Sloane, Dec 08 2000 STATUS approved

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Last modified July 23 12:19 EDT 2021. Contains 346259 sequences. (Running on oeis4.)