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 A333743 #8 Apr 04 2020 04:40:53 %S A333743 109,157,307,427,499,811,1015,1183,1459,2013,2251,2715,3181,3259,3439, %T A333743 3541,3889,3963,4303,4339,4553,4909,5197,6421,6661,6997,8389,8707, %U A333743 8779,9067,9109,9663,10531,10597,11731,12243,12259,13009,13789,14347,14437,14583,16143 %N A333743 Odd numbers k such that the multiplicative orders of 2 modulo k and modulo k+2 are equal. %H A333743 Amiram Eldar, <a href="/A333743/b333743.txt">Table of n, a(n) for n = 1..10000</a> %H A333743 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/MultiplicativeOrder.html">Multiplicative Order</a>. %H A333743 Wikipedia, <a href="https://en.wikipedia.org/wiki/Multiplicative_order">Multiplicative order</a>. %e A333743 109 is a term since the multiplicative orders of 2 modulo 109 and modulo 111 are both equal to 36. %t A333743 Select[Range[1, 10^4, 2], MultiplicativeOrder[2, #] == MultiplicativeOrder[2, # + 2] &] %Y A333743 Cf. A002326, A333741, A333744. %K A333743 nonn %O A333743 1,1 %A A333743 _Amiram Eldar_, Apr 03 2020