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A184808
n + floor(r*n), where r = sqrt(2/3); complement of A184809.
4
1, 3, 5, 7, 9, 10, 12, 14, 16, 18, 19, 21, 23, 25, 27, 29, 30, 32, 34, 36, 38, 39, 41, 43, 45, 47, 49, 50, 52, 54, 56, 58, 59, 61, 63, 65, 67, 69, 70, 72, 74, 76, 78, 79, 81, 83, 85, 87, 89, 90, 92, 94, 96, 98, 99, 101, 103, 105, 107, 108, 110, 112, 114, 116
OFFSET
1,2
COMMENTS
This is the Beatty sequence for 1 + sqrt(2/3).
Also, a(n) is the position of 2*n^2 in the sequence obtained by arranging all the numbers in the sets {2*h^2, h >= 1} and {3*k^2, k >= 1} in increasing order. - Clark Kimberling, Oct 20 2014
Also, numbers n such that floor((n+1)*sqrt(6)) - floor(n*sqrt(6)) = 2. - Clark Kimberling, Jul 15 2015
LINKS
FORMULA
a(n) = n + floor(r*n), where r = sqrt(2/3).
MATHEMATICA
r=(2/3)^(1/2); s=(3/2)^(1/2);
a[n_]:=n+Floor [n*r];
b[n_]:=n+Floor [n*s];
Table[a[n], {n, 1, 120}] (* A184808 *)
Table[b[n], {n, 1, 120}] (* A184809 *)
PROG
(Magma) [n+Floor(n*Sqrt(2/3)): n in [1..70]]; // Vincenzo Librandi, Oct 23 2014
(PARI)
main(size)={return(vector(size, n, n+floor(sqrt(2/3)*n)))} /* Anders Hellström, Jul 15 2015 */
CROSSREFS
Cf. A184809, A182760 (comment about joint ranking),
Sequence in context: A187318 A262770 A108598 * A329837 A214315 A249098
KEYWORD
nonn
AUTHOR
Clark Kimberling, Jan 22 2011
STATUS
approved