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 A367034 #24 Jan 18 2025 13:46:27
%S A367034 3,3,7,3,3,5,3,3,7,3,3,5,3,3,5,3,3,9,3,3,5,3,3,7,3,3,5,3,3,5,3,3,7,3,
%T A367034 3,5,3,3,9,3,3,5,3,3,5,3,3,9,3,3,5,3,3,7,3,3,5,3,3,5,3,3,9,3,3,5,3,3,
%U A367034 9,3,3,5,3,3,5,3,3,7,3,3,5,3,3,9,3,3,5,3,3,5,3,3,7,3,3,5,3,3,7,3,3,5,3,3,5
%N A367034 a(n) is the smallest odd number k > 1 for which the Jacobi symbol (n / k) >= 0.
%C A367034 This sequence is periodic with period P = 3*5*7 = 105.
%C A367034 All terms are in {3, 5, 7, 9}.
%H A367034 Antti Karttunen, <a href="/A367034/b367034.txt">Table of n, a(n) for n = 0..11025</a>
%F A367034 a(n + 105) = a(n).
%t A367034 a[n_] := Module[{k = 3}, While[JacobiSymbol[n, k] < 0, k += 2]; k]; Array[a, 105, 0]
%o A367034 (PARI) a(n) = my(k=3); while(kronecker(n,k)<0, k+=2); k; \\ _Michel Marcus_, Nov 02 2023
%Y A367034 Cf. A366973.
%K A367034 nonn,easy
%O A367034 0,1
%A A367034 _Amiram Eldar_ and _Thomas Ordowski_, Nov 02 2023