OFFSET
0,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..5000
P. J. C. Lamont, The number of Cayley integers of given norm, Proceedings of the Edinburgh Mathematical Society, 25.1 (1982): 101-103. See (6).
FORMULA
Sum_{k=0..n} a(k) ~ 30*zeta(4) * n^4. - Amiram Eldar, Dec 12 2023
MAPLE
with(numtheory);
rJ0 := proc(k) local n, d; n:=2*k+1; 16*add(d^3, d in divisors(n)); end;
[seq(rJ0(k), k=0..60)];
MATHEMATICA
16 DivisorSigma[3, Range[1, 75, 2]] (* Vincenzo Librandi, Sep 16 2018 *)
PROG
(Magma) [16*DivisorSigma(3, 2*n+1): n in [0..40]]; // Vincenzo Librandi, Sep 16 2018
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Sep 15 2018
STATUS
approved