A058271 An approximation to sigma_{3/2}(n): ceiling( sum_{d|n} d^(3/2) ).

1, 4, 7, 12, 13, 24, 20, 35, 34, 47, 38, 74, 48, 75, 76, 99, 72, 128, 84, 145, 121, 144, 112, 214, 138, 184, 174, 231, 158, 289, 174, 280, 233, 273, 238, 393, 227, 321, 297, 420, 264, 464, 283, 444, 405, 427, 324, 611, 363, 526, 441, 567, 387

Offset

1,2

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Formula

Sum_{k=1..n} a(k) ~ (2/5)*zeta(5/2) * n^(5/2). - 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^(3/2) end do; t2; end proc; # exact value of sigma_{3/2}(n)

Mathematica

a[n_] := Ceiling[DivisorSigma[3/2, n]]; Array[a, 50] (* Amiram Eldar, Jan 14 2023 *)

Crossrefs

Cf. A000203, A001157, A058269, A058270, A247041.

Sequence in context: A092574 A310769 A344598 * A332935 A244590 A310770

Adjacent sequences: A058268 A058269 A058270 * A058272 A058273 A058274

Keyword

nonn

Author

N. J. A. Sloane, Dec 08 2000

Status

approved