OFFSET
0,1
COMMENTS
REFERENCES
T. Nagell, Introduction to Number Theory, Chelsea Publishing Company, 1964, Theorem 109, pp. 207-208 with Theorem 104, pp. 197-198.
LINKS
FORMULA
a(n) = irrational part of z(n), where z(n) = (1+5*sqrt(2))*(3+2*sqrt(2))^n, n >= 0.
G.f.: (5-13*x)/(1-6*x+x^2).
a(n) = 6*a(n-1) - a(n-2), n >= 1, with a(-1) = 13 and a(0) = 5.
a(n) = 5*S(n, 6) - 13*S(n-1, 6), n >= 0, with Chebyshev's S-polynomials evaluated at x = 6 (see A049310).
EXAMPLE
PROG
(PARI) Vec((5-13*x)/(1-6*x+x^2) + O(x^30)) \\ Michel Marcus, Feb 08 2015
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Wolfdieter Lang, Feb 07 2015
STATUS
approved