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 A130337 #21 Sep 23 2021 11:13:16
%S A130337 1,2,3,12,24,84,195,780,924,29259,71484,2311539,23303784,208260975,
%T A130337 319589424,383229924,11962377504,178523171904
%N A130337 Where record values occur in A130335.
%F A130337 A130336(n) = A130335(a(n)).
%F A130337 A130335(k) < A130336(n) for k<a(n).
%t A130337 f[n_] := Block[{k = 1}, While[ GCD[n(n + 1)/2, (n + k)(n + k + 1)/2] != 1, k++ ]; k]; t = Table[0, {1000}]; Do[a = f@n; If[a < 1001 && t[[a]] == 0, t[[a]] = n; Print[{a, n}], If[a > 1000, Print[{"Over 1000", n}]]], {n, 2^31 - 1}] (* _Robert G. Wilson v_, Jun 03 2007 *)
%Y A130337 Cf. A130335, A130336.
%K A130337 nonn,more
%O A130337 1,2
%A A130337 _Reinhard Zumkeller_, May 28 2007
%E A130337 a(13)-a(16) from _Robert G. Wilson v_, Jun 03 2007
%E A130337 a(17) from _Chai Wah Wu_, Sep 16 2021
%E A130337 a(18) from _Chai Wah Wu_, Sep 23 2021