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 A023174 #18 Sep 22 2021 14:32:17 %S A023174 1,3,6,77,93,123,143,213,237,267,453,483,573,597,627,717,723,813,843, %T A023174 933,1077,1203,1227,1293,1317,1347,1437,1517,1563,1707,1763,1797,1803, %U A023174 1893,1923,2157,2253,2283,2307,2427,2517,2643,2691,2733,2757,2787,2973,3021 %N A023174 Numbers k such that Fibonacci(k) == 2 (mod k). %H A023174 Giovanni Resta, <a href="/A023174/b023174.txt">Table of n, a(n) for n = 1..10000</a> %t A023174 Select[Range[3100],Mod[Fibonacci[#]-2,#]==0&] (* _Harvey P. Dale_, Sep 22 2021 *) %o A023174 (PARI) is(n)=((Mod([1,1;1,0],n))^n)[1,2]==2 \\ _Charles R Greathouse IV_, Oct 28 2014 %Y A023174 Cf. A000045. %K A023174 nonn %O A023174 1,2 %A A023174 _David W. Wilson_