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 A255119 #24 Oct 13 2022 02:49:00
%S A255119 1,6,37,228,1404,8646,53244,327888,2019204,12434688,76575456,
%T A255119 471567960,2904015888,17883548064,110130696144,678208272192,
%U A255119 4176550921536,25720089706080,158389787869632,975398032747008,6006708734718528,36990591135528960
%N A255119 Number of n-length words on {0,1,2,3,4,5,6} in which 0 appears only in runs of length 2.
%H A255119 Colin Barker, <a href="/A255119/b255119.txt">Table of n, a(n) for n = 0..1000</a>
%H A255119 D. Birmajer, J. B. Gil, and M. D. Weiner, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL19/Gil/gil6.html">On the Enumeration of Restricted Words over a Finite Alphabet</a>, J. Int. Seq. 19 (2016) # 16.1.3. example 10.
%H A255119 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (6,0,6).
%F A255119 a(n+3) = 6*a(n+2) + 6*a(n) with n>1, a(0) = 1, a(1) = 6, a(2) = 37.
%F A255119 G.f.: -(x^2+1) / (6*x^3+6*x-1). - _Colin Barker_, Feb 15 2015
%t A255119 RecurrenceTable[{a[0] == 1, a[1] == 6, a[2]== 37, a[n] == 6 a[n - 1] + 6 a[n - 3]}, a[n], {n, 0, 20}]
%t A255119 LinearRecurrence[{6,0,6},{1,6,37},30] (* _Harvey P. Dale_, Nov 06 2017 *)
%o A255119 (PARI) Vec(-(x^2+1)/(6*x^3+6*x-1) + O(x^100)) \\ _Colin Barker_, Feb 15 2015
%Y A255119 Cf. A000930, A239333, A239340, A254657, A254600, A254664.
%K A255119 nonn,easy
%O A255119 0,2
%A A255119 _Milan Janjic_, Feb 14 2015