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 A270383 #26 Aug 29 2019 01:43:13
%S A270383 1,6,12,18,27,33,43,49,59,68,78,84,98,104,114,124,137,143,157,163,177,
%T A270383 187,197,203,221,230,240,250,264,270,288,294,308,318,328,338,359,365,
%U A270383 375,385,403,409,427,433,447,461,471,477,499,508,522
%N A270383 Number of ordered pairs (i,j) with i >= j, |i|, |j| <= n, and |i * j| <= n.
%H A270383 David A. Corneth, <a href="/A270383/b270383.txt">Table of n, a(n) for n = 0..9999</a>
%F A270383 a(n) = 2*(Sum_{k=1..n} tau(k)) + floor(sqrt(n)) + 2*n + 1, where tau(k) = A000005(k) is number of divisors of k.
%F A270383 a(n) = A067274(n) + 2 for n >= 1.
%e A270383 For n = 2 the a(2) = 12 pairs are (2,1), (2,0), (2,-1), (1,1), (1,0), (1,-1), (1,-2), (0,0), (0,-1), (0,-2), (-1,-1), and (-1,-2). - _Danny Rorabaugh_, Apr 05 2016
%t A270383 a[n_]:=2Sum[Length[Divisors[k]],{k,1,n}]+Floor[Sqrt[n]]+2n+1
%o A270383 (PARI) a(n) = 2*sum(k=1, n, numdiv(k)) + sqrtint(n) + 2*n + 1; \\ _Michel Marcus_, Apr 05 2016
%Y A270383 Cf. A000005, A067274, A226355.
%K A270383 nonn
%O A270383 0,2
%A A270383 _Lorenz H. Menke, Jr._, Mar 15 2016