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 A372033 #13 Apr 16 2024 19:05:17 %S A372033 1,1,3,7,18,46,121,323,875,2395,6611,18371,51337,144145,406420, %T A372033 1150126,3265412,9298372,26547710,75978322,217921336,626287520, %U A372033 1803176384,5200298000,15020569818,43447201226,125837214564,364911724264,1059404265599,3078918594707 %N A372033 The total number of levels visited by all Motzkin paths of length n. %H A372033 Alois P. Heinz, <a href="/A372033/b372033.txt">Table of n, a(n) for n = 0..1000</a> %H A372033 Wikipedia, <a href="https://en.wikipedia.org/wiki/Motzkin_number">Motzkin number</a> %F A372033 a(n) = A001006(n) + A333498(n). %p A372033 b:= proc(x, y, h) option remember; `if`(x=0, h+1, add( %p A372033 b(x-1, y+j, max(h, y)), j=-min(1, y)..min(1, x-y-1))) %p A372033 end: %p A372033 a:= n-> b(n, 0$2): %p A372033 seq(a(n), n=0..35); %Y A372033 Row sums of A372014. %Y A372033 Cf. A001006, A261003, A333498. %K A372033 nonn %O A372033 0,3 %A A372033 _Alois P. Heinz_, Apr 16 2024