OFFSET
1,2
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..1000
Index entries for linear recurrences with constant coefficients, signature (1,0,0,0,1,-1).
FORMULA
From Chai Wah Wu, May 30 2016: (Start)
a(n) = a(n-1) + a(n-5) - a(n-6), for n > 6.
G.f.: x*(x^5 + x^4 + x^3 + 3*x^2 + x + 1)/(x^6 - x^5 - x + 1). (End)
MATHEMATICA
Select[Range[100], MemberQ[{1, 2, 5, 6, 7}, Mod[#, 8]]&] (* Harvey P. Dale, Jan 16 2013 *)
LinearRecurrence[{1, 0, 0, 0, 1, -1}, {1, 2, 5, 6, 7, 9}, 50] (* G. C. Greubel, May 30 2016 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved