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 A228848 #24 Aug 06 2024 16:57:21 %S A228848 0,0,1,3,5,8,11,15,19,25,30,37,44,51,60,68,78,88,98,110,122,134,147, %T A228848 161,175,190,205,222,238,256,274,292,311,331,351,372,394,416,439,462, %U A228848 486,511,536,562,588,616,643,671,700,730,760,791,822,854,886,919,953 %N A228848 a(n) = round(3*n^2/Pi^2). %C A228848 a(n) is the asymptotic limit of A005728(n) and of A015614(n). %D A228848 Albert H. Beiler, Recreations in the theory of numbers, New York, Dover, (2nd ed.) 1966. See Table 71 at p. 171. %H A228848 Wikipedia, <a href="http://en.wikipedia.org/wiki/Farey_sequence">Farey sequence</a>. %F A228848 a(n) = round(A033428(n)/Pi^2). %F A228848 a(n) ~ A104141*n^2. %t A228848 Round[(3*Range[0,60]^2)/Pi^2] (* _Harvey P. Dale_, Dec 18 2013 *) %o A228848 (PARI) for(n=0, 56, print1(round(3*(n/Pi)^2), ", ")) %o A228848 (Sage) [round(3*n^2/pi^2) for n in range(0,57)] # _Stefano Spezia_, Aug 06 2024 %Y A228848 Cf. A000796, A005728, A015614, A104141. %K A228848 nonn,easy %O A228848 0,4 %A A228848 _Arkadiusz Wesolowski_, Sep 05 2013