This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A035205 #9 Nov 19 2023 01:28:07
%S A035205 1,2,0,3,0,0,2,4,1,0,2,0,2,4,0,5,0,2,2,0,0,4,1,0,1,4,0,6,2,0,0,6,0,0,
%T A035205 0,3,0,4,0,0,2,0,2,6,0,2,0,0,3,2,0,6,0,0,0,8,0,4,0,0,0,0,2,7,0,0,2,0,
%U A035205 0,0,0,4,2,0,0,6,4,0,2,0,1
%N A035205 Coefficients in expansion of Dirichlet series Product_p (1-(Kronecker(m,p)+1)*p^(-s)+Kronecker(m,p)*p^(-2s))^(-1) for m = 23.
%H A035205 Amiram Eldar, <a href="/A035205/b035205.txt">Table of n, a(n) for n = 1..10000</a>
%F A035205 From _Amiram Eldar_, Nov 19 2023: (Start)
%F A035205 a(n) = Sum_{d|n} Kronecker(23, d).
%F A035205 Multiplicative with a(23^e) = 1, a(p^e) = (1+(-1)^e)/2 if Kronecker(23, p) = -1 (p is in A038898), and a(p^e) = e+1 if Kronecker(23, p) = 1 (p = 2 or p is in A297177).
%F A035205 Asymptotic mean: Limit_{m->oo} (1/m) * Sum_{k=1..m} a(k) = 2*log(5*sqrt(23)+24)/sqrt(23) = 1.614221300924... . (End)
%t A035205 a[n_] := DivisorSum[n, KroneckerSymbol[23, #] &]; Array[a, 100] (* _Amiram Eldar_, Nov 19 2023 *)
%o A035205 (PARI) my(m = 23); direuler(p=2,101,1/(1-(kronecker(m,p)*(X-X^2))-X))
%o A035205 (PARI) a(n) = sumdiv(n, d, kronecker(23, d)); \\ _Amiram Eldar_, Nov 19 2023
%Y A035205 Cf. A038898, A297177.
%K A035205 nonn,easy,mult
%O A035205 1,2
%A A035205 _N. J. A. Sloane_