cp's OEIS Frontend

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.

A355309 Carmichael numbers ending in 3.

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%I A355309 #18 Jul 26 2022 13:38:53
%S A355309 52633,63973,334153,670033,997633,2508013,2628073,5968873,6733693,
%T A355309 13696033,15829633,15888313,18900973,26280073,27336673,46483633,
%U A355309 53711113,65241793,67653433,75765313,124630273,133344793,158864833,182356993,227752993,242641153,292244833,426821473,577240273,580565233,600892993
%N A355309 Carmichael numbers ending in 3.
%H A355309 Amiram Eldar, <a href="/A355309/b355309.txt">Table of n, a(n) for n = 1..10000</a>
%H A355309 <a href="/index/Ca#Carmichael">Index entries for sequences related to Carmichael numbers</a>
%t A355309 Select[10*Range[0, 10^7] + 3, CompositeQ[#] && Divisible[# - 1, CarmichaelLambda[#]] &] (* _Amiram Eldar_, Jul 25 2022 *)
%o A355309 (Python)
%o A355309 from itertools import count, islice
%o A355309 from sympy import factorint
%o A355309 def A355309_gen(): # generator of terms
%o A355309     for n in count(3,10):
%o A355309         f = factorint(n)
%o A355309         if len(f) == sum(f.values()) > 1 and not any((n-1) % (p-1) for p in f):
%o A355309             yield n
%o A355309 A355309_list = list(islice(A355309_gen(),5)) # _Chai Wah Wu_, Jul 26 2022
%Y A355309 Intersection of A002997 and A017305.
%Y A355309 Cf. A352970, A354609, A355305, A355307.
%K A355309 nonn,base
%O A355309 1,1
%A A355309 _Omar E. Pol_, Jul 25 2022