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 A187734 #38 Mar 09 2024 11:04:46
%S A187734 0,2,2,14,18,94,146,638,1138,4382,8658,30398,64818,212574,479890,
%T A187734 1496062,3525106,10581918,25748306,75139390,187301554,535144670,
%U A187734 1358396434,3820058238,9829858162,27316621854,71015537874,195595836350,512422576178,1401935442782
%N A187734 a(n) is the number of n-walks between the vertices 1 and 3 of the Graph on the chalkboard in 'Good Will Hunting', (1997).
%C A187734 For a presentation of the Graph, see the first link.
%D A187734 Burkard Polster & Marty Ross, Math Goes to the Movies, The Johns Hopkins University Press, Baltimore, 2013, ยง1.7 Mathematics: Graph Theory 1, pp. 9-12.
%H A187734 Oliver Knill, Harvard Math, <a href="http://www.math.harvard.edu/archive/21b_fall_03/goodwill/">The Good Will Hunting Problem</a>
%H A187734 Wikipedia, <a href="http://en.wikipedia.org/wiki/Good_Will_Hunting">Good Will Hunting</a>
%H A187734 MMDB-The Mathematical Movie Database, Burkard Polster & Marty Ross, <a href="http://www.qedcat.com/moviemath/GoodWill.htm">Good Will Hunting</a>
%H A187734 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (1,6,-4).
%F A187734 G.f.: 2*x^2/(1 - x - 6*x^2 + 4*x^3).
%e A187734 "For example, between the vertices 1 and 3, we can calculate that there are no 1-walks, two 2-walks, two 3-walks and so on. The resulting sequence of numbers begins 0, 2, 2, 14, 18, 94, 146, 638, ..." (p. 11).
%t A187734 LinearRecurrence[{1, 6, -4}, {0, 2, 2}, 30] (* Or *)
%t A187734 Rest@ CoefficientList[Series[2x^2/(1 - x - 6x^2 + 4x^3), {x, 0, 28}], x]
%o A187734 (PARI) Vec(2*x^2/(1 - x - 6*x^2 + 4*x^3)+O(x^99)) \\ _Charles R Greathouse IV_, May 21 2013
%K A187734 nonn,easy,walk
%O A187734 1,2
%A A187734 Oliver Knill (knill(AT)math.harvard.edu), Burkard Polster (burkard.polster(AT)monash.edu), Marty Ross (martinirossi(AT)gmail.com), and _Robert G. Wilson v_, Jan 02 2013