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%I #19 May 31 2021 12:55:34
%S 0,33,156,308,365,584,665,969,1380,1533,1700,2349,3185,3504,4745,5208,
%T 6956,9333,10220,11189,14960,19824,21681,28908,31605,41789,55640,
%U 60809,66456,88433,116781,127604,169725,185444,244800,325529,355656,388569,516660
%N Nonnegative values x of solutions (x, y) to the Diophantine equation x^2 + (x+511)^2 = y^2.
%H Vincenzo Librandi, <a href="/A207078/b207078.txt">Table of n, a(n) for n = 1..1000</a>
%H MathWorld, <a href="http://mathworld.wolfram.com/DiophantineEquation.html">Diophantine equation</a>
%H Wikipedia, <a href="http://en.wikipedia.org/wiki/Diophantine_equation">Diophantine equation</a>
%H <a href="/index/Rec#order_19">Index entries for linear recurrences with constant coefficients</a>, signature (1,0,0,0,0,0,0,0,6,-6,0,0,0,0,0,0,0,-1,1).
%F G.f.: x^2*(31*x^17 +89*x^16 +76*x^15 +23*x^14 +73*x^13 +23*x^12 +76*x^11 +89*x^10 +31*x^9 -153*x^8 -411*x^7 -304*x^6 -81*x^5 -219*x^4 -57*x^3 -152*x^2 -123*x -33)/((x -1)*(x^18 -6*x^9 +1)). [_Colin Barker_, Aug 05 2012]
%F a(n) = a(n-1)+6*a(n-9)-6*a(n-10)-a(n-18)+a(n-19). - _Wesley Ivan Hurt_, May 31 2021
%t LinearRecurrence[ {1, 0, 0, 0, 0, 0, 0, 0, 6, -6, 0, 0, 0, 0, 0, 0, 0, -1, 1}, {0, 33, 156, 308, 365, 584, 665, 969, 1380, 1533, 1700, 2349, 3185, 3504, 4745, 5208, 6956, 9333, 10220}, 50]
%Y Cf. A207060, A207061, A207075, A207076, A207077.
%K nonn,easy
%O 1,2
%A _Vladimir Joseph Stephan Orlovsky_, Feb 14 2012
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