A374913 - OEIS

%I #10 Aug 12 2024 13:30:00

%S 2,3,6,11,14,15,18,23,26,30,35,39,50,51,54,63,74,75,78,83,86,90,95,98,

%T 99,111,114,119,131,134,135,138,146,155,158,174,179,183,186,191,194,

%U 198,210,215,219,230,231,239,243,251,254,270,278,299,303,306,315,323,326,330,338,350

%N Numbers k such that k^(k + 1) == k + 1 (mod 2*k + 1).

%F Conjecture (Superseeker): a(n) = A263458(n)/2. - _R. J. Mathar_, Aug 02 2024

%t Select[Range[350],Mod[#^(#+1),2#+1]==#+1 &] (* _Stefano Spezia_, Jul 23 2024 *)

%o (Magma) [n: n in [0..350] | n^(n+1) mod (2*n+1) eq n+1];

%Y Supersequence of A002515 and A374914.

%Y Cf. A374912.

%K nonn

%O 1,1

%A _Juri-Stepan Gerasimov_, Jul 23 2024