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 A049635 #9 Aug 06 2021 04:52:46 %S A049635 2,7,11,16,23,32,39,50,63,74,89,106,117,138,159,174,199,224,241,270, %T A049635 299,320,349,384,409,442,481,508,549,594,621,668,707,740,791,834,869, %U A049635 922,979,1016,1073,1134,1169,1234,1299,1340,1403,1470,1517,1584,1655,1706 %N A049635 a(n) = T(n,n+3), array T as in A049627. %o A049635 (PARI) T(n,k) = (n+1)*(k+1) - sum(i=0, n, sum(j=0, k, gcd(i,j)>1)); \\ A049627 %o A049635 a(n) = T(n, n+3); \\ _Michel Marcus_, Aug 06 2021 %Y A049635 Cf. A049627. %K A049635 nonn %O A049635 0,1 %A A049635 _Clark Kimberling_ %E A049635 More terms from _Sean A. Irvine_, Aug 05 2021