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 A065134 #18 Jul 04 2016 13:19:37
%S A065134 0,1,0,2,0,3,0,1,2,1,2,1,2,3,4,3,4,3,4,5,6,5,6,7,8,0,1,9,0,9,10,0,1,2,
%T A065134 3,1,2,3,4,2,3,1,2,3,4,2,3,4,5,6,7,5,6,7,8,9,10,8,9,7,8,9,10,11,12,10,
%U A065134 11,12,13,11,12,10,11,12,13,14,15,13,14,15,16,14,15,16,17,18,19,17,18,19
%N A065134 Remainder when n is divided by the number of primes not exceeding n.
%C A065134 Also remainder when the number of nonprimes is divided by the number of primes (not exceeding n).
%H A065134 Harry J. Smith, <a href="/A065134/b065134.txt">Table of n, a(n) for n = 2..1000</a>
%F A065134 a(n) = n (mod pi(n)).
%e A065134 n = 2: Pi[2] = 1,Mod[1,1] = 0, the first term = a(2) = 0; n = 100: Pi[100] = 25, Mod[100,25] = 0 = a(100); n = 20: Pi[20] = 8, Mod[20,8] = 4 = a(20).
%t A065134 Table[Last@ QuotientRemainder[n, PrimePi[n]], {n, 2, 91}] (* _Michael De Vlieger_, Jul 04 2016 *)
%o A065134 (PARI) { for (n=2, 1000, write("b065134.txt", n, " ", n%primepi(n)) ) } \\ _Harry J. Smith_, Oct 11 2009
%Y A065134 Cf. A000720, A057809, A057810, A000040, A065134, A004648, A062298, A065858-A065864, A065133.
%K A065134 nonn
%O A065134 2,4
%A A065134 _Labos Elemer_, Oct 15 2001
%E A065134 Term a(1) removed so OFFSET changed from 1,5 to 2,4 by _Harry J. Smith_, Oct 11 2009
%E A065134 Since OFFSET is 2,4; Term a(1) removed and a(91) added by _Harry J. Smith_, Oct 11 2009