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 A127413 #14 Aug 02 2019 20:53:39
%S A127413 2,2,5,7,17,13,41,35,59,47,129,61,197,113,163,177,381,161,501,245,393,
%T A127413 345,791,311,805,515,813,569,1371,409,1593,895,1177,973,1519,793,2427,
%U A127413 1271,1753,1201,3087,963,3447,1707,2101,1989,4227,1531,4091,2009,3299
%N A127413 a(n) = Sum_{1<=k<=n, gcd(k,n)=1} prime(k).
%H A127413 Alois P. Heinz, <a href="/A127413/b127413.txt">Table of n, a(n) for n = 1..10000</a>
%F A127413 M * V where M = A054521 is an infinite lower triangular matrix and V = the sequence of primes (A000040) regarded as a vector.
%e A127413 a(9) = 59 since k ranges over {1, 2, 4, 5, 7, 8} and p(1) + p(2) + p(4) + p(5) + p(7) + p(8) = 2 + 3 + 7 + 11 + 17 + 19 = 59.
%p A127413 a:= n-> add(`if`(igcd(n, k)=1, ithprime(k), 0), k=1..n):
%p A127413 seq(a(n), n=1..60); # _Alois P. Heinz_, Oct 23 2009
%Y A127413 Cf. A054521.
%K A127413 nonn,easy,look
%O A127413 1,1
%A A127413 _Gary W. Adamson_, Jan 13 2007
%E A127413 More terms from _Alois P. Heinz_, Oct 23 2009