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 A282973 #24 Feb 16 2025 08:33:42
%S A282973 3,31,314159,314159265359
%N A282973 Primes in A011546.
%H A282973 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Pi-Prime.html">Pi-Prime</a>
%e A282973 a(5) = A011546(1902) = 314159...066118631 is a prime with 1902 digits.
%e A282973 a(6) = A011546(3971) = 314159...411010447.
%e A282973 a(7) = A011546(5827) = 314159...690496521.
%e A282973 a(8) = A011546(16208) = A005042(5) = 314159....943936307.
%e A282973 For n<=17511, there are eight primes in sequence A011546(n).
%e A282973 In addition, because of round(Pi*10^47576) = floor(Pi*10^47576), and A011546(47577)(=A005042(6)) is a prime. Thus, A011546(47577) will appear in here. A011546(613373)(=A005042(8)) as well. But A011546(78073)(=A005042(7)+1) is not prime.
%t A282973 Do[If[PrimeQ[Round[Pi*10^(n-1)]],Print[Round[Pi*10^(n-1)]]],{n,17511}]
%t A282973 Select[Module[{nn=20,pid},pid=RealDigits[Pi,10,nn+2][[1]];Table[Floor[(FromDigits[ Take[ pid,n+1]])/10+1/2],{n,nn}]],PrimeQ] (* _Harvey P. Dale_, Jan 01 2023 *)
%Y A282973 Cf. A011546, A282974, A000796, A005042.
%K A282973 nonn,base
%O A282973 1,1
%A A282973 _XU Pingya_, Feb 25 2017