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Terms of A122782 which are not Carmichael numbers A002997.
4

%I #12 Sep 19 2019 19:16:16

%S 1,4,10,15,20,65,124,190,217,310,435,781,1541,1891,3565,3820,4123,

%T 4495,5461,5611,5662,5731,6735,7449,7813,8029,8290,9881,11041,11476,

%U 12801,13021,13333,13981,14981,15751,16297,17767,20345,20710,21361,22791

%N Terms of A122782 which are not Carmichael numbers A002997.

%C Are there entries in this sequence which are also in A153513 ?

%C Yes. This subsequence starts 721801, 873181, 4504501, 8646121, 9006401, 9863461, 10403641, 10680265,... (similar to A153580). - _R. J. Mathar_, Mar 30 2011

%H Amiram Eldar, <a href="/A153515/b153515.txt">Table of n, a(n) for n = 1..10000</a>

%t Select[Range[10^4], !PrimeQ[#] && PowerMod[5, #, # ] == Mod[5, #] && Mod[#, CarmichaelLambda[#]] != 1 &] (* _Amiram Eldar_, Sep 19 2019 *)

%Y Cf. A002997, A122780, A153508, A153513.

%K nonn

%O 1,2

%A _Artur Jasinski_, Dec 28 2008