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 A178334 #12 Jan 09 2023 14:51:24
%S A178334 0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
%T A178334 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
%U A178334 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1
%N A178334 Number of mountain numbers <= n.
%C A178334 a(n) = 21846 for n >= 12345678987654321.
%H A178334 Reinhard Zumkeller, <a href="/A178334/b178334.txt">Table of n, a(n) for n = 0..20000</a>
%F A178334 a(n) = Sum_{k=0..n} A178333(k).
%o A178334 (Python)
%o A178334 from itertools import count, islice
%o A178334 def agen(): # generator of terms; uses code in A134941
%o A178334 A134941_full = A134941() + [-1]
%o A178334 c = i = 0
%o A178334 for j in count(0):
%o A178334 if j == A134941_full[i]: i, c = i+1, c+1
%o A178334 yield c
%o A178334 print(list(islice(agen(), 122))) # _Michael S. Branicky_, Jan 09 2023
%Y A178334 Cf. A135417.
%K A178334 nonn
%O A178334 0,122
%A A178334 _Reinhard Zumkeller_, May 25 2010