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 A049630 #10 Aug 06 2021 04:39:56
%S A049630 1,2,4,7,10,17,22,34,42,61,72,100,116,154,176,224,250,314,348,427,470,
%T A049630 563,612,726,786,918,988,1141,1220,1399,1492,1694,1802,2030,2148,2404,
%U A049630 2534,2820,2968,3284,3444,3796,3976,4361,4562,4979,5192,5654,5890,6389
%N A049630 a(n) = Sum_{i=0..floor(n/2)} T(2i,n-2i) where T is A049627.
%o A049630 (PARI) T(n,k) = (n+1)*(k+1) - sum(i=0, n, sum(j=0, k, gcd(i,j)>1)); \\ A049627
%o A049630 a(n) = sum(i=0, n\2, T(2*i,n-2*i)); \\ _Michel Marcus_, Aug 06 2021
%Y A049630 Cf. A049627.
%K A049630 nonn
%O A049630 0,2
%A A049630 _Clark Kimberling_
%E A049630 More terms from _Sean A. Irvine_, Aug 05 2021