OFFSET
0,7
LINKS
M. Brown and J. F. Slifker, Solution to Problem 6439, Amer. Math. Monthly, 92 (1985), p. 218.
M. Crampin, Piecewise linear recurrence relations, Math. Gaz., November 1992, p. 355.
Index entries for linear recurrences with constant coefficients, signature (0, 0, 0, 0, 0, 0, 0, 0, 1).
FORMULA
a(n) = a(n-9), with a(0)=0, a(1)=1, a(2)=1, a(3)=0, a(4)=-1, a(5)=1, a(6)=2, a(7)=1, a(8)=-1. - Harvey P. Dale, May 23 2014
MATHEMATICA
RecurrenceTable[{a[0]==0, a[1]==1, a[n]==Abs[a[n-1]]-a[n-2]}, a, {n, 100}] (* or *) LinearRecurrence[{0, 0, 0, 0, 0, 0, 0, 0, 1}, {0, 1, 1, 0, -1, 1, 2, 1, -1}, 100] (* or *) PadRight[{}, 100, {0, 1, 1, 0, -1, 1, 2, 1, -1}] (* Harvey P. Dale, May 23 2014 *)
CROSSREFS
KEYWORD
sign,easy
AUTHOR
Antonio G. Astudillo (afg_astudillo(AT)hotmail.com), Nov 07 2002
STATUS
approved