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 A385193 #26 Jun 28 2025 17:08:45 %S A385193 1,5,9,3,29,5,39,25,27,65,69,37,75,89,15,19,33,35,119,25,67,27,155, %T A385193 165,179,21,97,25,17,209,215,219,115,239,245,249,135,71,285,299,309, %U A385193 35,329,115,359,123,375,405,9,419,429,455,459,235,485,495,509,255,515,173,525,265,267,109,575,45 %N A385193 Odd multiplicative orders of 5 modulo primes. %C A385193 a(n) is the multiplicative order of 5 modulo A385192(n). %C A385193 Odd elements in A211241. %H A385193 Jianing Song, <a href="/A385193/b385193.txt">Table of n, a(n) for n = 1..10000</a> %e A385193 a(8) = 25 since it is the multiplicative order of 5 modulo A385192(8) = 101, and it is odd. %t A385193 Select[Map[MultiplicativeOrder[5, #] &, Prime[Range[200]]], OddQ] (* _Paolo Xausa_, Jun 28 2025 *) %o A385193 (PARI) forprime(p=2, 1e4, if(p!=5, z=znorder(Mod(5, p)); if(z%2, print1(z, ", ")))) %Y A385193 Cf. A211241, A385192 (corresponding primes). %Y A385193 Cf. other bases: A139686 (base 2), A385226 (base 3), A385227 (base 4), this sequence (base 5), A385228 (base -2), A385229 (base -3), A385230 (base -4), A385231 (base -5). %K A385193 nonn,easy %O A385193 1,2 %A A385193 _Jianing Song_, Jun 20 2025