OFFSET
0,3
COMMENTS
Apart from first term 0, these are the numbers such that the iterated sum-of-digits (A010888) is odd. - Michel Marcus, Jun 07 2015
Equivalently, numbers congruent to {0, 1, 3, 5, 7} mod 9. - Bruno Berselli, Jun 15 2016
LINKS
Index entries for linear recurrences with constant coefficients, signature (1,0,0,0,1,-1).
FORMULA
a(n) = n + floor(4*n/5).
a(n) = 2*n - 1 - floor((n - 1)/5). - Wesley Ivan Hurt, Jan 02 2017
From Chai Wah Wu, Oct 17 2022: (Start)
a(n) = a(n-1) + a(n-5) - a(n-6) for n > 5.
G.f.: x*(2*x^4 + 2*x^3 + 2*x^2 + 2*x + 1)/(x^6 - x^5 - x + 1). (End)
MAPLE
MATHEMATICA
Table[Floor[9 n/5], {n, 0, 120}]
PROG
(Magma) [Floor(9*n/5) : n in [0..100]]; // Wesley Ivan Hurt, Jan 02 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, Mar 08 2011
STATUS
approved