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 A098220 #9 Dec 23 2018 14:45:03 %S A098220 2,2,2,2,2,1,2,2,2,2,2,1,2,1,2,2,2,1,1,2,1,2,2,2,1,2,2,2,1,2,2,2,2,2, %T A098220 2,1,1,1,2,2,3,1,2,1,2,2,1,2,2,1,2,3,1,2,2,2,2,2,1,2,1,2,2,2,1,2,1,1, %U A098220 2,2,2,3,2,1,2,2,2,1,2,1,3,1,2,1,2,2,2,1,2,2,2,3,1,2,2,3,2,2,1,1,1,2,2,2,2 %N A098220 a(n) = floor(sigma(sigma(p))/p) = floor(sigma(p+1)/p) = floor(A008333(n)/p), where p is the n-th prime number. %C A098220 Values of these quotients are expectedly lower than ratios of A051027(n)/n. %e A098220 For n = 7, the seventh prime is 17, so a(7) = floor(sigma(sigma(17))/17) = floor(sigma(18)/17) = floor(39/17) = 2. %o A098220 (PARI) a(n) = my(p=prime(n)); sigma(p+1)\p; \\ _Michel Marcus_, Dec 23 2018 %Y A098220 Cf. A000203, A051027, A008333, A098219, A098221, A098222. %K A098220 nonn %O A098220 1,1 %A A098220 _Labos Elemer_, Oct 25 2004