login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A047556
Numbers that are congruent to {3, 6, 7} mod 8.
2
3, 6, 7, 11, 14, 15, 19, 22, 23, 27, 30, 31, 35, 38, 39, 43, 46, 47, 51, 54, 55, 59, 62, 63, 67, 70, 71, 75, 78, 79, 83, 86, 87, 91, 94, 95, 99, 102, 103, 107, 110, 111, 115, 118, 119, 123, 126, 127, 131, 134, 135, 139, 142, 143, 147, 150, 151, 155, 158, 159
OFFSET
1,1
FORMULA
G.f.: x*(1+x)*(x^2+3) / ((1+x+x^2)*(x-1)^2). - R. J. Mathar, Oct 08 2011
From Wesley Ivan Hurt, Jun 10 2016: (Start)
a(n) = a(n-1) + a(n-3) - a(n-4) for n>4.
a(n) = (24*n-9*cos(2*n*Pi/3)-sqrt(3)*sin(2*n*Pi/3))/9.
a(3k) = 8k-1, a(3k-1) = 8k-2, a(3k-2) = 8k-5. (End)
MAPLE
A047556:=n->(24*n-9*cos(2*n*Pi/3)-sqrt(3)*sin(2*n*Pi/3))/9: seq(A047556(n), n=1..100); # Wesley Ivan Hurt, Jun 10 2016
MATHEMATICA
Select[Range[0, 150], MemberQ[{3, 6, 7}, Mod[#, 8]] &] (* Wesley Ivan Hurt, Jun 10 2016 *)
LinearRecurrence[{1, 0, 1, -1}, {3, 6, 7, 11}, 60] (* Harvey P. Dale, Sep 02 2024 *)
PROG
(Magma) [n : n in [0..150] | n mod 8 in [3, 6, 7]]; // Wesley Ivan Hurt, Jun 10 2016
CROSSREFS
Sequence in context: A087642 A084349 A126003 * A255053 A292762 A374845
KEYWORD
nonn,easy
STATUS
approved