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 A100689 #19 Sep 08 2022 08:45:15
%S A100689 31,191,5119,114687,46137343,872415231,292057776127,5222680231935,
%T A100689 1618481116086271,8358680908399640575,142962266571249025023,
%U A100689 698910239464707491627007,198263834416799184651812863,3326963855579459488791396351,930930909542605966724141416447
%N A100689 a(n) = prime(n) * 4^prime(n) - 1.
%F A100689 a(n) = A060416(prime(n)) = A060416(A000040(n)). - _Michel Marcus_, Aug 27 2015
%e A100689 a(1) = 2*4^2 - 1 = 31.
%t A100689 Do[Print[Prime[n]*4^(Prime[n]) - 1], {n, 1, 20}] (* _Stefan Steinerberger_, Feb 15 2006 *)
%t A100689 # 4^#-1&/@Prime[Range[20]] (* _Harvey P. Dale_, Dec 06 2012 *)
%o A100689 (Magma) [NthPrime(n)*4^NthPrime(n) - 1: n in [1..20]]; // _Vincenzo Librandi_, Aug 27 2015
%o A100689 (PARI) vector(20, n, p=prime(n); p*4^p - 1) \\ _Michel Marcus_, Aug 27 2015
%K A100689 nonn
%O A100689 1,1
%A A100689 _Parthasarathy Nambi_, Dec 07 2004
%E A100689 More terms from _Stefan Steinerberger_, Feb 15 2006
%E A100689 a(14)-a(15) from _Vincenzo Librandi_, Aug 27 2015