OFFSET
1,3
COMMENTS
Numbers that are congruent to {0, 1, 2, 3, 4, 5, 6} mod 8.
Numbers n such that binary expansion does not end 111.
Complement of A004771. - Michel Marcus, Sep 11 2015
LINKS
Daniel Starodubtsev, Table of n, a(n) for n = 1..10000
Index entries for linear recurrences with constant coefficients, signature (1,0,0,0,0,0,1,-1).
FORMULA
G.f.: x^2*(1+x+x^2+x^3+x^4+x^5+2*x^6) / ((x^6+x^5+x^4+x^3+x^2+x+1)*(x-1)^2). - R. J. Mathar, Oct 08 2011
a(n) = floor((n-1)*8/7). - M. F. Hasler, Nov 02 2013
From Wesley Ivan Hurt, Sep 11 2015: (Start)
a(n) = a(n-1) + a(n-7) - a(n-8) for n>8.
a(n) = n - 1 + A132270(n). (End)
From Wesley Ivan Hurt, Jul 20 2016: (Start)
a(n) = (56*n - 77 + (n mod 7) + ((n+1) mod 7) + ((n+2) mod 7) + ((n+3) mod 7) + ((n+4) mod 7) + ((n+5) mod 7) - 6*((n+6) mod 7))/49.
a(7k) = 8k-2, a(7k-1) = 8k-3, a(7k-2) = 8k-4, a(7k-3) = 8k-5, a(7k-4) = 8k-6, a(7k-5) = 8k-7, a(7k-6) = 8k-8. (End)
MAPLE
MATHEMATICA
DeleteCases[Range[0, 100], _?(Mod[#, 8]==7&)] (* Harvey P. Dale, Apr 01 2011 *)
Select[Range[0, 100], ! MemberQ[{7}, Mod[#, 8]] &] (* Vincenzo Librandi, Sep 12 2015 *)
PROG
(PARI) A004777=n->(n-1)*8\7 \\ M. F. Hasler, Nov 02 2013
(Magma) [n-1+Floor((n-1)/7) : n in [1..100]]; // Wesley Ivan Hurt, Sep 11 2015
(Magma) [n: n in [0..100] | not n mod 8 in [7]]; // Vincenzo Librandi, Sep 11 2015
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
EXTENSIONS
Edited by N. J. A. Sloane Aug 31 2009 at the suggestion of R. J. Mathar.
STATUS
approved