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 A087023 #18 Jul 08 2023 13:45:38 %S A087023 3,2,4,2,2,2,2,3,3,5,2,2,2,2,2,4,3,3,3,2,2,2,2,3,3,3,5,2,2,2,5,2,7,2, %T A087023 3,2,2,5,3,4,2,3,2,2,2,3,3,2,6,2,3 %N A087023 Maximal exponent in prime factorization of n-th cyclic number. %C A087023 A004042(n) factorized with Dario Alpern's ECM. %C A087023 Extended using factors of 10^(A001913(n)-1)-1, see Kamada link. %H A087023 Dario A. Alpern, <a href="https://www.alpertron.com.ar/ECM.HTM">Factorization using the Elliptic Curve Method</a>. %H A087023 Makoto Kamada, <a href="https://stdkmd.net/nrr/repunit/">Factorizations of 11...11 (Repunit)</a> %H A087023 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/CyclicNumber.html">Cyclic Number</a> %F A087023 a(n) = A051903(A004042(n+1)). %e A087023 A004042(2) = 142857 = 37*13*11*3^3, therefore a(1) = 3. %Y A087023 Cf. A001913, A087020, A087021, A087022, A087024, A087025, A087026. %K A087023 nonn,more,hard %O A087023 1,1 %A A087023 _Reinhard Zumkeller_, Jul 30 2003 %E A087023 a(12)-a(42) from _Ray Chandler_, Nov 16 2011 %E A087023 a(43)-a(51) from _Max Alekseyev_, May 14 2022