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%I #28 Jun 13 2015 00:52:41
%S 0,25,532,29237,614312,33739857,708915900,38935766125,818088334672,
%T 44931840368777,944073229295972,51851304849802917,1089459688519217400,
%U 59836360864832197825,1257235536477947584012,69051108586711506487517,1450848719635862992732832
%N Expansion of x^2*(3*x^3+145*x^2-507*x-25) / ((x-1)*(x^2-34*x+1)*(x^2+34*x+1)).
%C Also the index of the first of two consecutive pentagonal numbers whose sum is also a pentagonal number. - _Colin Barker_, Dec 22 2014
%H Vincenzo Librandi, <a href="/A144942/b144942.txt">Table of n, a(n) for n = 1..200</a>
%H <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (1,1154,-1154,-1,1).
%t CoefficientList[Series[x (3 x^3 + 145 x^2 - 507 x - 25)/((x - 1) (x^2 - 34 x + 1) (x^2 + 34 x + 1)), {x, 0, 20}], x] (* _Vincenzo Librandi_, Oct 20 2014 *)
%o (PARI) concat(0, Vec(x^2*(3*x^3+145*x^2-507*x-25)/((x-1)*(x^2-34*x+1)*(x^2+34*x+1)) + O(x^20))) \\ _Colin Barker_, Oct 20 2014
%Y Cf. A133301, A144796, A144797.
%K easy,nonn
%O 1,2
%A _Richard Choulet_, Sep 26 2008
%E a(6) corrected, and more terms from _Colin Barker_, Oct 20 2014
%E Edited, name changed by _Colin Barker_, Oct 20 2014
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