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 A049631 #10 Aug 06 2021 04:44:47
%S A049631 0,2,4,7,12,17,26,34,50,61,84,100,132,154,198,224,280,314,384,427,514,
%T A049631 563,666,726,848,918,1062,1141,1306,1399,1586,1694,1912,2030,2274,
%U A049631 2404,2672,2820,3124,3284,3616,3796,4160,4361,4766,4979,5418,5654,6132,6389
%N A049631 a(n) = Sum_{i=0..floor(n/2)} T(2i+1,n-2i-1) where T is A049627.
%o A049631 (PARI) T(n,k) = (n+1)*(k+1) - sum(i=0, n, sum(j=0, k, gcd(i,j)>1)); \\ A049627
%o A049631 a(n) = sum(i=0, n\2, T(2*i+1, n-2*i-1)); \\ _Michel Marcus_, Aug 06 2021
%Y A049631 Cf. A049627.
%K A049631 nonn
%O A049631 0,2
%A A049631 _Clark Kimberling_
%E A049631 More terms and name corrected by _Sean A. Irvine_, Aug 05 2021