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 A004139 #24 Dec 16 2019 00:30:44
%S A004139 3,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,97,
%T A004139 101,103,107,109,113,127,131,137,139,149,151,157,163,167,173,179,181,
%U A004139 191,193,197,199,211,223,227,229,233,239,241
%N A004139 Odd primes excluding 5.
%C A004139 Subsequence of A007401. - _Reinhard Zumkeller_, Jul 18 2011
%C A004139 Primes not dividing 10. Therefore primes p for which the decimal expansion of 1/p does not terminate (primes in A085837). - _Jeppe Stig Nielsen_, Dec 15 2019
%D A004139 John H. Conway, R. K. Guy, The Book of Numbers, Copernicus Press, p. 162.
%H A004139 Michael De Vlieger, <a href="/A004139/b004139.txt">Table of n, a(n) for n = 1..10000</a>
%t A004139 Prime@ Delete[Range[2, 53], {2}] (* _Michael De Vlieger_, Dec 15 2019 *)
%o A004139 (PARI) a(n)=if(n>1,prime(n+2),3) \\ _Charles R Greathouse IV_, Aug 26 2011
%Y A004139 Subsequence of A065091, A007401, and A085837.
%K A004139 nonn,easy
%O A004139 1,1
%A A004139 _N. J. A. Sloane_