OFFSET
0,3
COMMENTS
Pisano period lengths: 1, 2, 1, 4, 4, 2, 48, 8, 1, 4, 10, 4, 84, 48, 4, 16, 272, 2, 360, 4, ... - R. J. Mathar, Aug 10 2012
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..900
Index entries for linear recurrences with constant coefficients, signature (10,9).
FORMULA
a(n) = 10*a(n-1) + 9*a(n-2).
a(n) = (-3*i)^(n-1) * ChebyshevU(n-1, -5*i/3). - G. C. Greubel, Feb 13 2021
MATHEMATICA
Join[{a=0, b=1}, Table[c=10*b+9*a; a=b; b=c, {n, 40}]] (* Vladimir Joseph Stephan Orlovsky, Mar 29 2011 *)
LinearRecurrence[{10, 9}, {0, 1}, 30] (* Vincenzo Librandi, Nov 15 2012 *)
Table[(-3 I)^(n - 1)*ChebyshevU[n - 1, 5 I/3], {n, 0, 30}] (* G. C. Greubel, Feb 13 2021 *)
PROG
(Sage) [lucas_number1(n, 10, -9) for n in range(0, 18)] # Zerinvary Lajos, Apr 26 2009
(Magma) [n le 2 select n-1 else 10*Self(n-1) + 9*Self(n-2): n in [1..30]]; // Vincenzo Librandi, Nov 15 2012
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
EXTENSIONS
Extended by T. D. Noe, May 23 2011
STATUS
approved