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 A131869 #29 Apr 20 2017 08:50:07
%S A131869 1,7,105,1967,41265,927479,21838425,531731935,13278739425,
%T A131869 338235642983,8753720757705,229531493157519,6084679071674385,
%U A131869 162802128960940119,4390789738688043705,119242319290800424383,3258012200816503807425,89495966923044854350535,2470171286283446551216425
%N A131869 Expansion of series reversion of x*(1-8*x)/(1-x).
%C A131869 The Hankel transform of this sequence is 56^C(n+1,2) .
%H A131869 G. C. Greubel, <a href="/A131869/b131869.txt">Table of n, a(n) for n = 1..675</a>
%F A131869 a(n) = Sum_{k=0..n} A086810(n,k)*7^k.
%F A131869 From _Vaclav Kotesovec_, Aug 20 2013: (Start)
%F A131869 G.f.: (x-15-sqrt(x^2-30*x+1))/16.
%F A131869 Recurrence: n*a(n) = 15*(2*n-3)*a(n-1) - (n-3)*a(n-2).
%F A131869 a(n) ~ sqrt(30*sqrt(14)-112)*(15+4*sqrt(14))^n/(16*sqrt(Pi)*n^(3/2)). (End)
%F A131869 G.f.: x/(1 - 7*x/(1 - 8*x/(1 - 7*x/(1 - 8*x/(1 - 7*x/(1 - ...)))))), a continued fraction. - _Ilya Gutkovskiy_, Apr 20 2017
%t A131869 Rest[CoefficientList[InverseSeries[Series[x*(1-8*x)/(1-x),{x,0,20}],x],x]] (* _Vaclav Kotesovec_, Aug 20 2013 *)
%o A131869 (PARI) Vec(serreverse(x*(1-8*x)/(1-x)+O(x^66))) /* _Joerg Arndt_, Feb 06 2013 */
%K A131869 nonn
%O A131869 1,2
%A A131869 _Philippe Deléham_, Oct 29 2007
%E A131869 More terms from _Philippe Deléham_, Feb 06 2013
%E A131869 Offset corrected, _Joerg Arndt_, Feb 15 2013