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 A037066 #17 Jul 21 2025 00:22:40
%S A037066 1,4,59,275,4924,58623,506877,4546755,30224014,87818618,2836649805,
%T A037066 14748299309,251285857122,603200604933,17530836835060,80446298927642,
%U A037066 2054098188682332,9577010472498628,67026825574168206,1605887402218872982,16520076587958693329,156502536697199220470
%N A037066 a(n)-th prime is the smallest prime containing exactly n 7's.
%H A037066 Andrew R. Booker, <a href="https://t5k.org/nthprime/">The Nth Prime Page</a>.
%H A037066 Kim Walisch, <a href="https://github.com/kimwalisch/primecount">primecount</a>, Fast prime counting function library.
%F A037066 a(n) = A000720(A037067(n)). - _Amiram Eldar_, Jul 21 2025
%t A037066 (* see A037067 for f *) PrimePi[ Table[ f[n, 7], {n, 1, 12}]]
%Y A037066 Cf. A000720, A037067, A034388.
%Y A037066 Cf. A037052, A037054, A037056, A037058, A037060, A037062, A037064, A037068, A037070.
%K A037066 nonn,base,hard
%O A037066 0,2
%A A037066 _Patrick De Geest_, Jan 04 1999
%E A037066 a(0)=1 prepended by _Sean A. Irvine_, Dec 06 2020
%E A037066 a(14)-a(21) calculated using Kim Walisch's primecount and added by _Amiram Eldar_, Jul 21 2025