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A182691
Composite Beatty sequence of sqrt(2).
1
3, 4, 13, 18, 61, 86, 293, 414, 1413, 1998, 6821, 9646, 32933, 46574, 159013, 224878, 767781, 1085806, 3707173, 5242734, 17899813, 25314158, 86427941, 122227566, 417311013, 590166894, 2014955813, 2849577838, 9729067301
OFFSET
1,1
COMMENTS
The bisection (4,18,86,...) is a subsequence of A001951.
The bisection (3,13,61,...) is a subsequence of A001952.
See the comment at A107857 regarding Beatty sequences.
LINKS
FORMULA
a(n) = floor(s*a(n-1)) if n odd, a(n)=floor(r*a(n-1)) if n even, where r=sqrt(2), s=2+r, a(1)=floor(s).
EXAMPLE
a(1)=floor(2+sqrt(2))=3, a(2)=floor(r*a(1))=4.
MAPLE
Digits := 16 ;
A182691 := proc(n) option remember; local r, s ; r := sqrt(2) ; s := 2+r ; if n = 1 then floor(s) ; elif type(n, 'odd') then floor(s*procname(n-1)) ; else floor(r*procname(n-1)) ; end if; end proc:
seq(A182691(n), n=1..30) ;
MATHEMATICA
a[1]:= 3; a[n_]:= If[OddQ[n], Floor[(2+Sqrt[2])*a[n-1]], Floor[Sqrt[2]*a[n-1]]]; Table[a[n], {n, 1, 50}] (* G. C. Greubel, Sep 29 2018 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Clark Kimberling, Nov 27 2010
STATUS
approved