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 A083740 #17 Jun 29 2019 10:32:03 %S A083740 29341,46657,75361,88831,115921,146611,162401,252601,294409,314821, %T A083740 334153,340561,399001,410041,488881,512461,530881,552721,658801, %U A083740 721801,852841,954271,1024651,1152271,1193221,1314631,1461241,1569457,1615681 %N A083740 Pseudoprimes to bases 3,5 and 7. %H A083740 Amiram Eldar, <a href="/A083740/b083740.txt">Table of n, a(n) for n = 1..8702</a> (terms 1..77 from R. J. Mathar) %H A083740 F. Richman, <a href="http://math.fau.edu/Richman/carm.htm">Primality testing with Fermat's little theorem</a> %F A083740 a(n) = n-th positive integer k(>1) such that 3^(k-1) = 1 (mod k), 5^(k-1) = 1 (mod k) and 7^(k-1) = 1 (mod k). %F A083740 Intersection of A083734 and A005938. Intersection of A083735 and A005936. - _R. J. Mathar_, Apr 05 2011 %e A083740 a(1)=29341 since it is the first number such that 3^(k-1) = 1 (mod k), 5^(k-1) = 1 (mod k) and 7^(k-1) = 1 (mod k). %t A083740 Select[Range[1, 10^5, 2], CompositeQ[#] && PowerMod[3, #-1, #] == PowerMod[5, #-1, #] == PowerMod[7, #-1, #] == 1&] %Y A083740 Cf. A005935, A005936, A005938, A083734, A083735. %K A083740 easy,nonn %O A083740 1,1 %A A083740 Serhat Sevki Dincer (sevki(AT)ug.bilkent.edu.tr), May 05 2003