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%I #8 Jan 14 2023 08:45:41
%S 1,4,7,12,13,24,20,35,34,47,38,74,48,75,76,99,72,128,84,145,121,144,
%T 112,214,138,184,174,231,158,289,174,280,233,273,238,393,227,321,297,
%U 420,264,464,283,444,405,427,324,611,363,526,441,567,387
%N An approximation to sigma_{3/2}(n): ceiling( sum_{d|n} d^(3/2) ).
%H Amiram Eldar, <a href="/A058271/b058271.txt">Table of n, a(n) for n = 1..10000</a>
%F Sum_{k=1..n} a(k) ~ (2/5)*zeta(5/2) * n^(5/2). - _Amiram Eldar_, Jan 14 2023
%p 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)
%t a[n_] := Ceiling[DivisorSigma[3/2, n]]; Array[a, 50] (* _Amiram Eldar_, Jan 14 2023 *)
%Y Cf. A000203, A001157, A058269, A058270, A247041.
%K nonn
%O 1,2
%A _N. J. A. Sloane_, Dec 08 2000
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