A121780 - OEIS

%I #11 Oct 06 2019 13:05:18

%S 0,8,66,444,2541,12840,59113,253600,1029802,4002112,15005189,54603436,

%T 193743969,672725072,2292470170,7685026612,25392243845,82826447752,

%U 267077278409,852322922488,2694626921682,8446754831544

%N Series expansion for mean-squared radius of gyration of stack polygons on square lattice.

%H I. Jensen, <a href="/A121780/b121780.txt">Table of n, a(n) for n = 1..55</a> (from link below)

%H I. Jensen, <a href="https://researchers.ms.unimelb.edu.au/~ij@unimelb/polygons/Polygons_ser.html">Series expansions for self-avoiding polygons</a>

%F Empirical g.f.: x^2*(8 - 54*x + 214*x^2 - 489*x^3 + 605*x^4 - 386*x^5 + 177*x^6 - 120*x^7 + 19*x^8 - x^9) / (1 - 3*x + x^2)^5. - _Colin Barker_, Apr 17 2017

%K nonn

%O 1,2

%A _N. J. A. Sloane_, Aug 30 2006