OFFSET
1,2
LINKS
Vincenzo Librandi, 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
G.f.: x^2*(2+x+2*x^2+x^3+2*x^4) / ( (x^4+x^3+x^2+x+1)*(x-1)^2 ). - R. J. Mathar, Dec 07 2011
From Wesley Ivan Hurt, Jul 31 2016: (Start)
a(n) = a(n-1) + a(n-5) - a(n-6) for n > 6, a(n) = a(n-5) + 8 for n > 5.
a(n) = (40*n - 40 + 3*(n mod 5) - 2*((n+1) mod 5) + 3*((n+2) mod 5) - 2*((n+3) mod 5) - 2*((n+4) mod 5))/25.
a(5k) = 8k-2, a(5k-1) = 8k-3, a(5k-2) = 8k-5, a(5k-3) = 8k-6, a(5k-4) = 8k-8. (End)
MAPLE
A047448:=n->8*floor(n/5)+[(0, 2, 3, 5, 6)][(n mod 5)+1]: seq(A047448(n), n=0..100); # Wesley Ivan Hurt, Jul 31 2016
MATHEMATICA
Select[Range[0, 100], MemberQ[{0, 2, 3, 5, 6}, Mod[#, 8]] &] (* Wesley Ivan Hurt, Jul 31 2016 *)
LinearRecurrence[{1, 0, 0, 0, 1, -1}, {0, 2, 3, 5, 6, 8}, 70] (* Harvey P. Dale, Feb 08 2022 *)
PROG
(Magma) [n : n in [0..150] | n mod 8 in [0, 2, 3, 5, 6]]; // Wesley Ivan Hurt, Jul 31 2016
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved