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 A184967 #18 Sep 08 2022 08:45:55 %S A184967 1,2,4,5,6,8,9,10,12,13,16,20,21,22,24,25,26,28,29,30,32,33,34,36,37, %T A184967 41,42,44,45,46,48,50,52,54,56,57,58,60,61,62,64,65,66,68,72,73,74,76, %U A184967 77,78,80,81,84,85,86,88,90,92,93,94,96,98,100,101,102,104,105,106,108,109,110,112,113,114,116,120,121,122 %N A184967 Numbers k such that k^k+1 is squarefree. %C A184967 5^5+1 = 3126 = 2*3*521. %C A184967 6^6+1 = 46657 = 13*37*97. %C A184967 8^8 = 16777217 = 97*257*673. %t A184967 Select[Range@46,SquareFreeQ[#^#+1]&] %o A184967 (Magma) [ n: n in [1..60] | IsSquarefree(n^n+1) ]; // _Bruno Berselli_, Mar 24 2011 %o A184967 (PARI) isok(k) = issquarefree(k^k+1); \\ _Michel Marcus_, Feb 22 2021 %Y A184967 Cf. A005117, A014566, A184966. %K A184967 nonn %O A184967 1,2 %A A184967 _Vladimir Joseph Stephan Orlovsky_, Mar 19 2011 %E A184967 Extended by _Bruno Berselli_, Mar 24 2011 %E A184967 a(39)-a(78) from _Amiram Eldar_, Feb 22 2021