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 A228145 #27 Sep 08 2022 15:57:47 %S A228145 3,4,8,9,10,16,18,31,34,39,41,42,55,68,79,90,95,97,114,122,148,151, %T A228145 160,209,265,320,329,441,457,516,529,632,640,682,712,791,1056,1169, %U A228145 1632,1943,2200,2279,2468,2698,2921,2996,3129,3140,3656,3960,4889,5560,5895 %N A228145 Numbers k such that 2*Fibonacci(k) - 1 is prime. %H A228145 Jorge Coveiro, <a href="/A228145/b228145.txt">Table of n, a(n) for n = 1..62</a> (first 55 terms from Vincenzo Librandi) %t A228145 Select[Range[2000], PrimeQ[2 Fibonacci[#] - 1]&] %o A228145 (Magma) [n: n in [1..1700] | IsPrime(2*Fibonacci(n)-1)]; %o A228145 (PARI) is(n)=ispseudoprime(2*fibonacci(n)-1) \\ _Charles R Greathouse IV_, Jun 13 2017 %Y A228145 Cf. A000045, A124067. %K A228145 nonn %O A228145 1,1 %A A228145 _Vincenzo Librandi_, Aug 13 2013