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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.

A385723 Numbers k such that m^m == m (mod k) where m = ceiling(k/2).

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%I A385723 #23 Jul 20 2025 21:25:44
%S A385723 1,2,6,7,10,14,17,18,22,23,26,30,31,34,38,41,42,46,47,50,54,58,62,66,
%T A385723 70,71,73,74,78,79,82,86,89,90,94,97,98,102,103,106,110,113,114,118,
%U A385723 122,126,127,130,134,137,138,142,146,150,151,154,158,162,166,167,170
%N A385723 Numbers k such that m^m == m (mod k) where m = ceiling(k/2).
%p A385723 q:= k-> (m-> 0=m&^m-m mod k)(ceil(k/2)):
%p A385723 select(q, [$1..200])[];  # _Alois P. Heinz_, Jul 08 2025
%t A385723 m[k_]:=Ceiling[k/2]; Select[Range[170], PowerMod[m[#], m[#], #]==Mod[m[#],#] &] (* _Stefano Spezia_, Jul 08 2025 *)
%o A385723 (Magma) [k: k in [1..200] | Modexp(m, m, k) eq m mod k where m is Ceiling(k/2)];
%o A385723 (PARI) isok(k) = my(m=ceil(k/2)); m == Mod(m, k)^m; \\ _Michel Marcus_, Jul 08 2025
%Y A385723 Superset of A001132 and A016825.
%Y A385723 Cf. A004526.
%K A385723 nonn
%O A385723 1,2
%A A385723 _Juri-Stepan Gerasimov_, Jul 07 2025