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%I #18 Dec 07 2015 22:54:58
%S 0,170,13622,6672192,534017484,261563278454,20934553401986,
%T 10253803635289356,820676361930645528,401969609849050063298,
%U 32172154719470612594510,15758012635048656946126680,1261212808492010592999343332,617745610917207839753008053902
%N Values of n such that the sum of the 7-gonal number (5*n^2 - 3*n)/2 and the following 7-gonal number is a 7-gonal number.
%C Both bisections of the sequence satisfy the recurrence relation a(n+2) = 39202*a(n+1) - a(n) + 7840.
%C Also nonnegative integers x in the solution to 10*x^2-5*y^2+4*x+3*y+2 = 0, the corresponding values of y being A133327. - _Colin Barker_, Dec 05 2014
%H Colin Barker, <a href="/A133328/b133328.txt">Table of n, a(n) for n = 1..436</a>
%H <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (1,39202,-39202,-1,1).
%F G.f.: 2*x^2*(6*x^3+2885*x^2-6726*x-85) / ((x-1)*(x^2-198*x+1)*(x^2+198*x+1)). - _Colin Barker_, Dec 05 2014
%o (PARI) concat(0, Vec(2*x^2*(6*x^3+2885*x^2-6726*x-85)/((x-1)*(x^2-198*x+1)*(x^2+198*x+1)) + O(x^100))) \\ _Colin Barker_, Dec 05 2014
%Y Cf. A133324, A133327.
%K nonn,easy
%O 1,2
%A _Richard Choulet_, Oct 18 2007
%E More terms from _Colin Barker_, Dec 05 2014
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