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 A066913 #17 Aug 06 2019 20:34:06
%S A066913 0,0,2,3,0,5,3,7,5,0,6,11,2,4,3,7,7,17,1,10,4,20,8,23,20,7,16,7,13,29,
%T A066913 5,30,14,5,8,11,12,24,25,30,33,16,23,4,3,26,46,35,27,21,2,1,10,52,35,
%U A066913 36,17,2,27,10,13,34,50,51,28,23,32,5,59,64,0,58,55,7,29,7,1,70,1
%N A066913 (sum of primes < n that do not divide n) (mod n).
%H A066913 Harvey P. Dale, <a href="/A066913/b066913.txt">Table of n, a(n) for n = 1..1000</a>
%F A066913 a(n) = A066911(n) modulo n. - _Michel Marcus_, May 20 2014
%F A066913 a(prime(n)) = A071089(n). - _Michel Marcus_, May 20 2014
%e A066913 a(8) = (3 + 5 + 7) (mod 8) = 7 because 3, 5 and 7 are the primes < 8 that do not divide 8.
%t A066913 Table[Mod[Total[Select[Prime[Range[PrimePi[n]]],Mod[n,#]!=0&]],n],{n,80}] (* _Harvey P. Dale_, Aug 06 2019 *)
%o A066913 (PARI) a(n) = sum(i=1, n-1, if (isprime(i) && (n%i), i)) % n; \\ _Michel Marcus_, May 20 2014
%Y A066913 Cf. A066911, A071089.
%K A066913 nonn
%O A066913 1,3
%A A066913 _Leroy Quet_, Jan 22 2002