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 A362256 #6 Apr 19 2023 02:47:46
%S A362256 1,1,1,5,9,13,17,25,37,53,73,101,141,197,273,377,521,721,997,1377,
%T A362256 1901,2625,3625,5005,6909,9537,13165,18173,25085,34625,47793,65969,
%U A362256 91057,125685,173481,239453,330513,456201,629685,869141,1199657,1655861,2285549,3154693
%N A362256 a(0) = a(1) = a(2) = 1, for n > 2, a(n) = a(n-1) + a(n-k) + k with k = 3.
%C A362256 Called Leonardo 3-numbers in the Tan-Leung paper.
%H A362256 Elif Tan and Ho-Hon Leung, <a href="https://doi.org/10.5281/zenodo.7569221">On Leonardo p-Numbers</a>, Integers (2023) Vol. 23, #A7. See p. 2.
%H A362256 <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (2,-1,0,1,-1).
%t A362256 LinearRecurrence[{2, -1, 0, 1, -1}, {1, 1, 1, 5, 9}, 44] (* or *)
%t A362256 With[{p = 3}, Nest[Append[#, #[[-1]] + #[[-p - 1]] + p] &, {1, 1, 1, 5}, 40] ]
%Y A362256 Cf. A001595, A111314, A362255.
%K A362256 nonn,easy
%O A362256 0,4
%A A362256 _Michael De Vlieger_, Apr 13 2023