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.

A099188 a(n) = 2*ceiling(n/sqrt(2)).

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%I A099188 #21 Jan 28 2023 10:37:42
%S A099188 0,2,4,6,6,8,10,10,12,14,16,16,18,20,20,22,24,26,26,28,30,30,32,34,34,
%T A099188 36,38,40,40,42,44,44,46,48,50,50,52,54,54,56,58,58,60,62,64,64,66,68,
%U A099188 68,70,72,74,74,76,78,78,80,82,84,84,86,88,88,90,92,92,94,96,98,98,100
%N A099188 a(n) = 2*ceiling(n/sqrt(2)).
%C A099188 Conjecturally, length of shortest polygonal path from (0,0) to (n,n) with integer vertices and edges. This is true for n <= 10000.
%H A099188 Reinhard Zumkeller, <a href="/A099188/b099188.txt">Table of n, a(n) for n = 0..10000</a>
%F A099188 a(n) = 2*A049474(n).
%t A099188 2Ceiling[Range[0,80]/Sqrt[2]] (* _Harvey P. Dale_, Dec 21 2011 *)
%o A099188 (PARI) a(n)=if(n,2+2*sqrtint((n^2-1)\2)) \\ _Charles R Greathouse IV_, Jan 10 2013
%o A099188 (Haskell)
%o A099188 a099188 = (* 2) . a049474  -- _Reinhard Zumkeller_, Jul 03 2015
%o A099188 (Magma) [2*Ceiling(n/Sqrt(2)): n in [0..100]]; // _G. C. Greubel_, Aug 17 2018
%K A099188 nonn,easy
%O A099188 0,2
%A A099188 _David W. Wilson_, Mar 26 2005