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 A346018 #7 Jul 01 2021 16:11:41 %S A346018 1,1,2,2,2,3,2,3,3,4,4,4,4,4,5,2,4,5,5,5,6,6,6,6,6,6,6,7,4,6,6,7,7,7, %T A346018 7,8,6,6,8,8,8,8,8,8,9,4,8,8,8,9,9,9,9,9,10,10,10,10,10,10,10,10,10, %U A346018 10,10,11,4,6,8,10,10,11,11,11,11,11,11,12 %N A346018 Triangle read by rows: T(n,k) is the number of integers m such that 1 <= m <= n and gcd(m,n) <= k, 1 <= k <= n. %F A346018 T(n,1) = A000010(n). %F A346018 T(n,2) = A126246(n). %F A346018 T(n,k) = n-1 for A032742(n) <= k <= n-1. %F A346018 T(n,n) = n. %e A346018 Triangle begins: %e A346018 n\k 1 2 3 4 5 6 7 8 9 10 %e A346018 ---------------------------------- %e A346018 1: 1 %e A346018 2: 1 2 %e A346018 3: 2 2 3 %e A346018 4: 2 3 3 4 %e A346018 5: 4 4 4 4 5 %e A346018 6: 2 4 5 5 5 6 %e A346018 7: 6 6 6 6 6 6 7 %e A346018 8: 4 6 6 7 7 7 7 8 %e A346018 9: 6 6 8 8 8 8 8 8 9 %e A346018 10: 4 8 8 8 9 9 9 9 9 10 %o A346018 (PARI) T(n,k) = sum(m=1, n, gcd(m, n) <= k); \\ _Michel Marcus_, Jul 01 2021 %Y A346018 Cf. A000010 (column k=1), A126246 (column k=2), A032742. %K A346018 nonn,tabl %O A346018 1,3 %A A346018 _Pontus von Brömssen_, Jul 01 2021