OFFSET
0,2
LINKS
Colin Barker, Table of n, a(n) for n = 0..1000
D. Birmajer, J. B. Gil, and M. D. Weiner, On the Enumeration of Restricted Words over a Finite Alphabet, J. Int. Seq. 19 (2016) # 16.1.3, example 10.
Index entries for linear recurrences with constant coefficients, signature (4,0,4).
FORMULA
a(n+3) = 4*a(n+2) + 4*a(n) with n>1, a(0) = 1, a(1) = 4, a(2) = 17.
G.f.: -(x^2+1) / (4*x^3+4*x-1). - Colin Barker, Feb 15 2015
MATHEMATICA
RecurrenceTable[{a[0] == 1, a[1] == 4, a[2]== 17, a[n] == 4 a[n - 1] + 4 a[n - 3]}, a[n], {n, 0, 25}]
PROG
(PARI) Vec(-(x^2+1)/(4*x^3+4*x-1) + O(x^100)) \\ Colin Barker, Feb 15 2015
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Milan Janjic, Feb 14 2015
STATUS
approved