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 A242630 #9 Aug 17 2024 11:08:49
%S A242630 1,7,48,329,2254,15443,105804,724892,4966431,34026362,233123809,
%T A242630 1597194268,10942809918,74972150416,513654479985,3519185768909,
%U A242630 24110893526041,165190252745398,1131763100053353,7754015102916294,53124854674462893,363972747889200054
%N A242630 Number of n-length words w over a 7-ary alphabet {a_1,...,a_7} such that w contains never more than j consecutive letters a_j (for 1<=j<=7).
%H A242630 Geoffrey Critzer and Alois P. Heinz, <a href="/A242630/b242630.txt">Table of n, a(n) for n = 0..1000</a>
%H A242630 <a href="/index/Rec#order_21">Index entries for linear recurrences with constant coefficients</a>, signature (4, 13, 33, 61, 106, 157, 220, 277, 331, 364, 382, 369, 340, 289, 233, 170, 117, 70, 39, 17, 6).
%F A242630 G.f.: -(x+1) *(x^2+1) *(x^4+1) *(x^6+x^5+x^4+x^3+x^2+x+1) *(x^2+x+1) *(x^2-x+1) *(x^4+x^3+x^2+x+1) / (6*x^21 +17*x^20 +39*x^19 +70*x^18 +117*x^17 +170*x^16 +233*x^15 +289*x^14 +340*x^13 +369*x^12 +382*x^11 +364*x^10 +331*x^9 +277*x^8 +220*x^7 +157*x^6 +106*x^5 +61*x^4 +33*x^3 +13*x^2 +4*x-1).
%Y A242630 Column k=7 of A242464.
%K A242630 nonn,easy
%O A242630 0,2
%A A242630 _Geoffrey Critzer_ and _Alois P. Heinz_, May 19 2014