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 A282974 #37 Jun 16 2025 16:25:46
%S A282974 1,2,6,12,1902,3971,5827,16208,47577
%N A282974 Numbers k such that A011546(k-1) is a prime.
%C A282974 Round(k)=floor(k) or floor(k)+1, so if round(k)=floor(k) and floor(k) is a prime number, then round(k) is also prime. Thus 47577 = A060421(6) and 613373 = A060421(8) are also terms.
%C A282974 The corresponding primes are in A282973.
%C A282974 a(10) > 2^16. - _Lucas A. Brown_, Apr 05 2021
%H A282974 Lucas A. Brown, <a href="https://github.com/lucasaugustus/oeis/blob/main/A282974.py">A282974.py</a>
%H A282974 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Pi-Prime.html">Pi-Prime</a>
%t A282974 Do[If[PrimeQ[Round[Pi*10^(n-1)]],Print[n]],{n,17511}]
%o A282974 (PARI) default(realprecision, 10^5); x=Pi;
%o A282974 is(k) = ispseudoprime(round(x*10^k--)); \\ _Jinyuan Wang_, Mar 27 2020
%Y A282974 Cf. A000796, A005042, A011546, A060421, A282973.
%K A282974 nonn,base,more,hard
%O A282974 1,2
%A A282974 _XU Pingya_, Feb 25 2017
%E A282974 a(8) and a(9) from _Lucas A. Brown_, Apr 05 2021
%E A282974 Definition corrected by _Lucas A. Brown_, Apr 05 2021