cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A049473 Nearest integer to n/sqrt(2).

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%I A049473 #26 Sep 08 2022 08:44:58
%S A049473 0,1,1,2,3,4,4,5,6,6,7,8,8,9,10,11,11,12,13,13,14,15,16,16,17,18,18,
%T A049473 19,20,21,21,22,23,23,24,25,25,26,27,28,28,29,30,30,31,32,33,33,34,35,
%U A049473 35,36,37,37,38,39,40,40,41,42,42,43,44,45,45,46,47,47
%N A049473 Nearest integer to n/sqrt(2).
%C A049473 a(n) = floor(n*sqrt(2)) - floor(n/sqrt(2)). Indeed, the equation {(nearest integer to n/r) = floor(nr) - floor(n/r) for all n>=0} has exactly two solutions: sqrt(2) and -sqrt(2). - _Clark Kimberling_, Dec 18 2003
%C A049473 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, in positions given by the nonhomogeneous Beatty sequences A001954 and A001953, respectively.  - _Clark Kimberling_, Oct 05 2014
%H A049473 G. C. Greubel, <a href="/A049473/b049473.txt">Table of n, a(n) for n = 0..10000</a>
%t A049473 Round[Range[0,70]/Sqrt[2]] (* _Harvey P. Dale_, Feb 17 2015 *)
%o A049473 (PARI) a(n)=round(n/sqrt(2)) \\ _Charles R Greathouse IV_, Sep 02 2015
%o A049473 (Magma) [0] cat [Round(n/Sqrt(2)): n in [1..100]]; // _G. C. Greubel_, Jan 27 2018
%Y A049473 Cf. A091087.
%K A049473 nonn
%O A049473 0,4
%A A049473 _N. J. A. Sloane_