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 A069042 #21 Mar 13 2025 12:39:28 %S A069042 1,2,17,37,1153,1303 %N A069042 Numbers k such that A000364(k) == 1 (mod k^2). %t A069042 Select[Range[1, 10000], Divisible[Abs[EulerE[2*#]] - 1, #^2] &] (* _Amiram Eldar_, Jun 03 2017 *) %o A069042 (PARI) is(k) = Mod(abs(eulerfrac(2*k)), k^2) == 1; \\ _Jinyuan Wang_, Mar 13 2025 %Y A069042 Cf. A000364, A081730. %K A069042 nonn,more %O A069042 1,2 %A A069042 _Benoit Cloitre_, Apr 06 2003 %E A069042 More terms from _Hans Havermann_, Apr 07 2003 %E A069042 a(1) prepended by _Jinyuan Wang_, Mar 13 2025