OFFSET
1,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
Eric Weisstein's World of Mathematics, Diophantine equation.
Wikipedia, Diophantine equation.
Index entries for linear recurrences with constant coefficients, signature (1,0,0,0,0,0,0,0,6,-6,0,0,0,0,0,0,0,-1,1).
FORMULA
G.f.: x^2*(77*x^17 +75*x^16 +61*x^15 +12*x^14 +47*x^13 +12*x^12 +61*x^11 +75*x^10 +77*x^9 -371*x^8 -325*x^7 -227*x^6 -40*x^5 -141*x^4 -32*x^3 -139*x^2 -125*x -91)/((x -1)*(x^18 -6*x^9 +1)). - Colin Barker, Aug 05 2012
MATHEMATICA
LinearRecurrence[ {1, 0, 0, 0, 0, 0, 0, 0, 6, -6, 0, 0, 0, 0, 0, 0, 0, -1, 1}, {0, 91, 216, 355, 387, 528, 568, 795, 1120, 1491, 1960, 2635, 3408, 3588, 4387, 4615, 5916, 7791, 9940}, 50]
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vladimir Joseph Stephan Orlovsky, Feb 14 2012
STATUS
approved