OFFSET
0,3
LINKS
Michael De Vlieger, Table of n, a(n) for n = 0..852
S. Barbero, U. Cerruti, and N. Murru, On polynomial solutions of the Diophantine equation (x + y - 1)^2 = wxy, Rendiconti Sem. Mat. Univ. Pol. Torino (2020) Vol. 78, No. 1, 5-12.
Index entries for linear recurrences with constant coefficients, signature (16,-16,1).
FORMULA
a(n) = 2*(T(n, 15/2)-1)/13 with twice the Chebyshev polynomials of the first kind evaluated at x=15/2: 2*T(n, 15/2)=A078365(n)= ((15+sqrt(221))^n +(15-sqrt(221))^n)/2^n.
a(n) = 15*a(n-1) - a(n-2) + 2, n>=2, a(0)=0, a(1)=1.
a(n) = 16*a(n-1) - 16*a(n-2) + a(n-3), n>=3, a(0)=0, a(1)=1, a(2)=17.
G.f.: x*(1+x)/((1-x)*(1-15*x+x^2)) = x*(1+x)/(1-16*x+16*x^2-x^3) (from the Stephan link, see A092184).
MATHEMATICA
LinearRecurrence[{# - 1, -# + 1, 1}, {0, 1, #}, 18] &[17] (* Michael De Vlieger, Feb 23 2021 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Wolfdieter Lang, Oct 18 2004
STATUS
approved