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 A372771 #27 Mar 14 2025 20:23:02
%S A372771 1,2,4,6,8,9,10,12,14,16,18,20,22,24,25,26,28,30,32,33,34,36,38,40,42,
%T A372771 44,46,48,49,50,52,54,56,57,58,60,62,64,66,68,70,72,73,74,76,78,80,81,
%U A372771 82,84,86,88,90,92,94,96,98,100,102,104,105,106,108,110
%N A372771 Numbers m such that the congruence x^(m+1) == m (mod m+1) is solvable.
%C A372771 Includes all positive even numbers. - _Robert Israel_, Mar 14 2025
%H A372771 Robert Israel, <a href="/A372771/b372771.txt">Table of n, a(n) for n = 1..10000</a>
%e A372771 9 is a term because x^(9+1) == 9 (mod 9+1) for x = 3 and x = 7, i.e., 3^10 = 59049 == 9 (mod 10) and 7^10 = 282475249 == 9 (mod 10).
%p A372771 select(m -> traperror(NumberTheory:-ModularRoot(m,m+1,m+1))::integer, [$1..200]); # _Robert Israel_, Mar 14 2025
%t A372771 Select[Range[1, 110], With[{m = #}, AnyTrue[Range[1, m + 1], PowerMod[#, m + 1, m + 1] == m &]] &] (* _Robert P. P. McKone_, May 14 2024 *)
%Y A372771 Cf. A014117, A330279, A371811.
%K A372771 nonn
%O A372771 1,2
%A A372771 _Juri-Stepan Gerasimov_, May 12 2024
%E A372771 Terms corrected by _Robert P. P. McKone_, May 14 2024