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 A244621 #20 Jul 19 2014 14:38:19 %S A244621 1,5,7,7,11,5,7,7,11,1,1,7,5,5,1,11,7,1,1,5,11,11,7,5,11,1,1,5,11,1,1, %T A244621 5,7,7,5,5,11,11,7,5,1,7,11,5,7,7,7,7,11,5,7,11,5,1,11,7,5,5,11,1,1, %U A244621 11,11,7,1,11,11,5 %N A244621 (First arithmetic derivative of primorials) read mod 12. %C A244621 A024451 as numerator of Sum_{i = 1..n} 1/prime(i) is the first arithmetic derivative of primorials prime(n)# of A002110. a(n) shows the distribution of A024451 over four residual classes. %F A244621 a(n) = (prime(n)#)' mod 12 or a(n) = A024451(n) mod 12. %e A244621 a(4) = [(prime(4)#)' = (4#)' = (210)' = 247] mod 12 = 7, %e A244621 a(6) = [(prime(6)#)' = (13#)' = (30030)' = 40361] mod 12 = 5. %o A244621 (PARI) a(n) = numerator(sum(i=1, n, 1/prime(i))) % 12; \\ _Michel Marcus_, Jul 07 2014 %Y A244621 Cf. A002110, A024451, A003415, A244622. %K A244621 nonn %O A244621 1,2 %A A244621 _Freimut Marschner_, Jul 02 2014