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 A384014 #15 May 20 2025 11:48:24
%S A384014 0,1,16,108,834,6893,58659,510839,4515301,40477023,366751460,
%T A384014 3352789726,30877698604,286159371452,2666303391801,24959756192476,
%U A384014 234610874384116,2213224276178123,20945897352118544,198802912201260034,1891788092230264832,18044365524165259927,172479703095316537972
%N A384014 a(n) is the number of n-digit terms in A384013.
%H A384014 Tomás Oliveira e Silva, <a href="https://sweet.ua.pt/tos/primes.html">Tables of values of pi(x) and of pi2(x)</a>
%t A384014 a[1]:=0; a[n_]:=Module[{count=0},For[k=Prime[PrimePi[10^(n-1)]+1], k<=Prime[PrimePi[10^n-1]],k=NextPrime[k],If[Part[d=IntegerDigits[k],1]==Part[d,2],count++]]; count]; Array[a,7]
%Y A384014 Cf. A383979, A384013, A384016.
%K A384014 nonn,base
%O A384014 1,3
%A A384014 _Stefano Spezia_, May 17 2025
%E A384014 a(11)-a(23) from _David Radcliffe_, May 17 2025