login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A001953 a(n) = floor((n + 1/2) * sqrt(2)).
(Formerly M0543 N0193)
6

%I M0543 N0193 #98 Sep 08 2022 08:44:29

%S 0,2,3,4,6,7,9,10,12,13,14,16,17,19,20,21,23,24,26,27,28,30,31,33,34,

%T 36,37,38,40,41,43,44,45,47,48,50,51,53,54,55,57,58,60,61,62,64,65,67,

%U 68,70,71,72,74,75,77,78,79,81,82,84,85,86,88,89,91,92,94,95

%N a(n) = floor((n + 1/2) * sqrt(2)).

%C Let s(n) = zeta(3) - Sum_{k = 1..n} 1/k^3. Conjecture: for n >= 1, s(a(n)) < 1/n^2 < s(a(n)-1), and the difference sequence of A049473 consists solely of 0's and 1's, in positions given by the nonhomogeneous Beatty sequences A001954 and A001953, respectively. - _Clark Kimberling_, Oct 05 2014

%D N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

%H T. D. Noe, <a href="/A001953/b001953.txt">Table of n, a(n) for n = 0..10000</a>

%H Ian G. Connell, <a href="http://dx.doi.org/10.4153/CMB-1959-024-3">A generalization of Wythoff's game</a>, Canad. Math. Bull. 2 (1959) 181-190.

%H N. J. A. Sloane, <a href="/A115004/a115004.txt">Families of Essentially Identical Sequences</a>, Mar 24 2021 (Includes this sequence)

%F From _Ralf Steiner_, Oct 23 2019: (Start)

%F a(n) = floor(2*sqrt(A000217(n))).

%F a(n) = A136119(n + 1) - 1.

%F a(n + 1) - a(n) is in {1,2}.

%F a(n + 3) - a(n) is in {4,5}. (End)

%p seq( floor((2*n+1)/sqrt(2)), n=0..100); # _G. C. Greubel_, Nov 14 2019

%t Table[Floor[(n + 1/2) Sqrt[2]], {n, 0, 100}] (* _T. D. Noe_, Aug 17 2012 *)

%o (PARI) a(n)=floor((n+1/2)*sqrt(2))

%o (PARI) a(n)={sqrtint(2*n*(n+1))} \\ _Andrew Howroyd_, Oct 24 2019

%o (Magma) [Floor((2*n+1)/Sqrt(2)): n in [0..100]]; // _G. C. Greubel_, Nov 14 2019

%o (Sage) [floor((2*n+1)/sqrt(2)) for n in (0..100)] # _G. C. Greubel_, Nov 14 2019

%Y Complement of A001954.

%Y Cf. A000217 (T), A136119, A001108.

%K nonn

%O 0,2

%A _N. J. A. Sloane_

%E More terms from _Michael Somos_, Apr 26 2000.

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 18 22:18 EDT 2024. Contains 371782 sequences. (Running on oeis4.)