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A047399
Numbers that are congruent to {0, 3, 6} mod 8.
6
0, 3, 6, 8, 11, 14, 16, 19, 22, 24, 27, 30, 32, 35, 38, 40, 43, 46, 48, 51, 54, 56, 59, 62, 64, 67, 70, 72, 75, 78, 80, 83, 86, 88, 91, 94, 96, 99, 102, 104, 107, 110, 112, 115, 118, 120, 123, 126, 128, 131, 134, 136, 139, 142, 144, 147, 150, 152, 155, 158
OFFSET
1,2
FORMULA
a(n) = a(n-1) + a(n-3) - a(n-4) for n>4.
a(n) = floor((8*n-6)/3). [Gary Detlefs, Mar 07 2010]
a(n) = 3*n-floor(n/3). [Gary Detlefs, Jul 09 2011]
G.f. x^2*(3+3*x+2*x^2) / ((1+x+x^2)*(x-1)^2). - R. J. Mathar, Oct 08 2011
From Wesley Ivan Hurt, Jun 13 2016: (Start)
a(n) = (24*n-21+3*cos(2*n*Pi/3)-sqrt(3)*sin(2*n*Pi/3))/9.
a(3k) = 8k-2, a(3k-1) = 8k-5, a(3k-2) = 8k-8. (End)
MAPLE
seq(floor((8*n-6)/3), n=1..52); # Gary Detlefs, Mar 07 2010
MATHEMATICA
f[n_] := 3 n - Floor[n/3]; Array[f, 52, 0] (* Or *)
Cases[ Range[0, 136], n_ /; MatchQ[ Mod[n, 8], 0 | 3 | 6]] (* Robert G. Wilson v, Jul 10 2011 *)
PROG
(Magma) [Floor((8*n-6)/3): n in [1..60]]; // Vincenzo Librandi, Jul 11 2011
CROSSREFS
Sequence in context: A004957 A026352 A198084 * A342744 A057349 A087068
KEYWORD
nonn,easy
STATUS
approved