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%I #23 Dec 12 2023 08:01:00
%S 16,448,2016,5504,12112,21312,35168,56448,78624,109760,154112,194688,
%T 252016,327040,390240,476672,596736,693504,810464,984704,1102752,
%U 1272128,1526112,1661184,1887888,2201472,2382048,2685312,3073280,3286080,3631712,4166528,4431168,4812224
%N a(n) = 16 times the sum of the cubes of the divisors of 2*n+1.
%H Vincenzo Librandi, <a href="/A318937/b318937.txt">Table of n, a(n) for n = 0..5000</a>
%H P. J. C. Lamont, <a href="https://doi.org/10.1017/S001309150000420X">The number of Cayley integers of given norm</a>, Proceedings of the Edinburgh Mathematical Society, 25.1 (1982): 101-103. See (6).
%F Sum_{k=0..n} a(k) ~ 30*zeta(4) * n^4. - _Amiram Eldar_, Dec 12 2023
%p with(numtheory);
%p rJ0 := proc(k) local n,d; n:=2*k+1; 16*add(d^3, d in divisors(n)); end;
%p [seq(rJ0(k),k=0..60)];
%t 16 DivisorSigma[3, Range[1, 75, 2]] (* _Vincenzo Librandi_, Sep 16 2018 *)
%o (Magma) [16*DivisorSigma(3, 2*n+1): n in [0..40]]; // _Vincenzo Librandi_, Sep 16 2018
%Y Equals 16 times A045823.
%Y Cf. A013662.
%K nonn,easy
%O 0,1
%A _N. J. A. Sloane_, Sep 15 2018
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