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 A136582 #22 Dec 06 2023 15:22:57
%S A136582 3,31,3162277,316227766016837933,316227766016837933199889354443271
%N A136582 Sqrt(10)-primes: primes obtained by concatenating the first digits in the decimal expansion of sqrt(10).
%C A136582 n such that floor(sqrt(10^(2*n-1))) is prime (1, 2, 7, 18, 33, ...) are given in A136583.
%C A136582 This sequence is the list of prime terms in A017934.
%C A136582 The next term has 206 digits. - _Harvey P. Dale_, Dec 06 2023
%F A136582 a(n) = A017934(2*A136583(n)-1).
%t A136582 Module[{nn=50,sq10},sq10=RealDigits[Sqrt[10],10,nn][[1]];Select[FromDigits/@Table[Take[sq10,n],{n,nn}],PrimeQ]] (* _Harvey P. Dale_, Dec 06 2023 *)
%o A136582 (Magma) // by _Jason Kimberley_, Aug 2011
%o A136582 for n in [1..499 by 2] do
%o A136582 f := Isqrt(10^n);
%o A136582 if IsPrime(f) then
%o A136582 printf "%o,", f;
%o A136582 end if;
%o A136582 end for;
%Y A136582 Cf. A010467, A017934, A017934, A131581, A132153, A136583, A175733, A175734.
%K A136582 nonn,base
%O A136582 1,1
%A A136582 _Lekraj Beedassy_, Jan 09 2008