OFFSET
1,2
LINKS
Colin Barker, Table of n, a(n) for n = 1..300
Index entries for linear recurrences with constant coefficients, signature (974,-1).
FORMULA
G.f.: x*(1-x) / (1-974*x+x^2).
a(n) = 974*a(n-1) - a(n-2) for n>2.
a(n) = ((487 + 36*sqrt(183))^(-n)*(2 - 9*sqrt(3/61) + (2+9*sqrt(3/61))* (487 + 36*sqrt(183))^(2*n)))/4.
EXAMPLE
973 is in the sequence because 973^2 = 946729 = ((4387+1)^3-4387^3)/61.
MATHEMATICA
LinearRecurrence[{974, -1}, {1, 973}, 50] (* G. C. Greubel, Jul 15 2016 *)
PROG
(PARI) Vec(x*(1-x)/(1-974*x+x^2) + O(x^20))
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Colin Barker, Jul 15 2016
STATUS
approved