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 A113238 #15 Jun 23 2024 04:09:05
%S A113238 0,1,2,3,5,6,9,11,12,17,20,22,23,31,37,40,42,43,57,68,74,77,79,80,105,
%T A113238 125,136,142,145,147,148,193,230,250,261,267,270,272,273,355,423,460,
%U A113238 480,491,497,500,502,503,653,778,846,883,903,914,920,923,925,926,1201
%N A113238 Differences of nonzero tribonacci numbers.
%F A113238 {a(n)} = { A000073(i) - A000073(j) such that i>=j>=2 }.
%t A113238 Union[Flatten[Differences/@Subsets[Drop[LinearRecurrence[{1, 1, 1}, {0, 0, 1}, 16],2],{2}]]] (* _James C. McMahon_, Jun 22 2024 *)
%Y A113238 Cf. A000073, A001590 (subset), A113239 (primes in this sequence).
%K A113238 easy,nonn
%O A113238 1,3
%A A113238 _Jonathan Vos Post_, Oct 19 2005