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 A081523 #6 May 24 2020 04:00:35
%S A081523 1,4,12,16,20,54,35,64,72,130,77
%N A081523 Sum of terms in row n of A081521.
%o A081523 (PARI) a(n) = {my(m=n*(n-1)/2, v); forstep(k=m+n/(2-n%2), oo, n, v=List([]); for(i=2, k-m, if(gcd(n, i)==1, listput(v, i))); if(#v>n-2, forsubset([#v, n-1], w, if(r=1+sum(i=1, n-1, v[w[i]])==k, return(k))))); } \\ _Jinyuan Wang_, May 23 2020
%Y A081523 Cf. A081521, A081522, A081524.
%K A081523 nonn,more
%O A081523 1,2
%A A081523 _Amarnath Murthy_, Mar 27 2003
%E A081523 a(8)-a(11) from _Jinyuan Wang_, May 23 2020