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 A057857 #4 Jul 15 2016 14:27:34 %S A057857 1,2,4,11,52,485,5766,92167,1658888,36495369,1021870090,30656102411, %T A057857 1103619686412,44144787456013,1854081073152014,85287729364992015, %U A057857 4434961926979584016,257227791764815872017,15433667505888952320018 %N A057857 Number of residue classes modulo n-th primorial number which contain a prime. %F A057857 a(n) = A005867(n)+n = A002110(n) - A057858(n). %e A057857 a(3) = 11 since 30 is the 3rd primorial number and 30k+m can be prime if m = 2, 3 or 5 (once each with k = 0) or m = 1, 7, 11, 13, 17, 19, 23 or 29 (each for an infinite number of values of k). %Y A057857 Cf. A002110, A005867, A057858. %K A057857 nonn %O A057857 0,2 %A A057857 _Henry Bottomley_, Sep 08 2000