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 A036142 #10 Jul 08 2025 21:35:13 %S A036142 1,3,9,27,81,17,51,40,7,21,63,76,2,6,18,54,49,34,102,80,14,42,13,39,4, %T A036142 12,36,108,98,68,91,47,28,84,26,78,8,24,72,103,83,23,69,94,56,55,52, %U A036142 43,16,48,31,93,53,46,25,75,112 %N A036142 3^n mod 113. %D A036142 I. M. Vinogradov, Elements of Number Theory, pp. 220 ff. %p A036142 [ seq(primroot(ithprime(i))^j mod ithprime(i),j=0..100) ]; %t A036142 PowerMod[3,Range[0,80],113] (* _Harvey P. Dale_, Jul 26 2023 *) %o A036142 (PARI) a(n)=lift(Mod(3,113)^n) \\ _Charles R Greathouse IV_, Mar 22 2016 %K A036142 nonn,easy %O A036142 0,2 %A A036142 _N. J. A. Sloane_