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 A141883 #12 Sep 08 2022 08:45:35 %S A141883 29,89,109,149,229,269,349,389,409,449,509,569,709,769,809,829,929, %T A141883 1009,1049,1069,1109,1129,1229,1249,1289,1409,1429,1489,1549,1609, %U A141883 1669,1709,1789,1889,1949,2029,2069,2089,2129,2269,2309,2389,2549,2609,2689,2729 %N A141883 Primes congruent to 9 mod 20. %H A141883 Vincenzo Librandi, <a href="/A141883/b141883.txt">Table of n, a(n) for n = 1..1000</a> %t A141883 Select[Range[9,5000,20],PrimeQ[#]&] (* _Vladimir Joseph Stephan Orlovsky_, Mar 31 2011*) %o A141883 (Magma) [p: p in PrimesUpTo(3000) | p mod 20 eq 9 ]; // _Vincenzo Librandi_, Aug 16 2012 %o A141883 (PARI) is(n)=isprime(n) && n%20==9 \\ _Charles R Greathouse IV_, Jul 01 2016 %Y A141883 Cf. A000040, A105854, A141881, A141882. %K A141883 nonn,easy %O A141883 1,1 %A A141883 _N. J. A. Sloane_, Jul 11 2008