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A058273 An approximation to sigma_{5/2}(n): round( sum_{d|n} d^(5/2) ). 3
1, 7, 17, 39, 57, 110, 131, 220, 260, 379, 402, 641, 610, 870, 944, 1244, 1193, 1728, 1575, 2200, 2167, 2678, 2538, 3644, 3182, 4063, 4048, 5050, 4530, 6283, 5352, 7036, 6674, 7939, 7434, 10035, 8328, 10482, 10125, 12500, 10765, 14426 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
FORMULA
Sum_{k=1..n} a(k) ~ (2/7)*zeta(7/2) * n^(7/2). - Amiram Eldar, Jan 14 2023
MAPLE
f := proc(n) local d, t1, t2; t2 := 0; t1 := divisors(n); for d in t1 do t2 := t2 + d^(5/2) end do; t2; end proc; # exact value of sigma_{5/2}(n)
MATHEMATICA
a[n_] := Round[DivisorSigma[5/2, n]]; Array[a, 50] (* Amiram Eldar, Jan 14 2023 *)
CROSSREFS
Sequence in context: A253663 A298369 A213789 * A058274 A322597 A360428
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Dec 08 2000
STATUS
approved

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Last modified June 12 17:29 EDT 2024. Contains 373349 sequences. (Running on oeis4.)