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.
%I A258911 #22 Sep 08 2022 08:46:12
%S A258911 1,1,3,9,26,73,204,568,1581,4399,12239,34051,94736,263571,733297,
%T A258911 2040150,5676024,15791606,43934770,122233545,340073237,946138039,
%U A258911 2632307076,7323498533,20375142114,56686898249,157712000980
%N A258911 a(1)=a(2)=1, a(n) = ceiling(Pi*a(n-1) - a(n-2)), n>2.
%C A258911 Ratio of consecutive terms approaches (Pi + sqrt(Pi^2 - 4))/2, or approximately 2.782159649779516149316 (A189039).
%H A258911 G. C. Greubel, <a href="/A258911/b258911.txt">Table of n, a(n) for n = 1..1000</a>
%e A258911 a(3) = ceiling(Pi*1 - 1) = 3;
%e A258911 a(4) = ceiling(Pi*3 - 1) = 9;
%e A258911 a(5) = ceiling(Pi*9 - 3) = 26.
%t A258911 RecurrenceTable[{a[n] == Ceiling[Pi*a[n - 1] - a[n - 2]], a[1] == 1,
%t A258911 a[2] == 1}, a, {n,1,50}] (* _G. C. Greubel_, Jun 03 2017 *)
%t A258911 nxt[{a_,b_}]:={b,Ceiling[b*Pi-a]}; NestList[nxt,{1,1},30][[All,1]] (* _Harvey P. Dale_, Apr 02 2020 *)
%o A258911 (Magma) I:=[1,1]; [n le 2 select I[n] else Ceiling(pi*Self(n-1)-Self(n-2)): n in [1..200]];
%o A258911 (PARI) main(size)={my(v=vector(size),i);v[1]=1;v[2]=1;for(i=3,size,v[i]=ceil(Pi*v[i-1]-v[i-2]));return(v);} /* _Anders Hellström_, Jul 14 2015 */
%Y A258911 Cf. A189039.
%K A258911 nonn
%O A258911 1,3
%A A258911 _Morris Neene_, Jun 14 2015