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 A228641 #10 Aug 29 2013 13:45:37 %S A228641 2,17,59,140,274,473,752,1122,1598,2193,2919,3789,4818,6018,7402,8983, %T A228641 10775,12791,15043,17545,20311,23353,26685,30319,34269,38548,43169, %U A228641 48146,53491,59217,65338,71868,78818,86203,94035,102328,111094,120347,130101,140367,151160 %N A228641 Volume of torus (rounded down) with major radius = n and minor radius = n/3. %H A228641 K. D. Bajpai, <a href="/A228641/b228641.txt">Table of n, a(n) for n = 1..100</a> %H A228641 Wikipedia, <a href="http://en.wikipedia.org/wiki/Torus">Torus</a> %F A228641 a(n) = floor( 2/9 * Pi^2 * n^3 ). %e A228641 a(6) = 473 : volume = ((2 *Pi * n) * (Pi * (n/3)^2)) = ((2 *Pi * 6) * (Pi * (6/3)^2)) = 473.7410114 and floor(473.7410114) = 473. %p A228641 KD := proc() local a; a:=floor( evalf( (2*Pi*n)*(Pi*(n/3)^2) ) ); RETURN (a) :end: seq(KD(),n=1..50); %o A228641 (PARI) a(n)=floor(2/9*Pi^2*n^3) \\ _Charles R Greathouse IV_, Aug 28 2013 %Y A228641 Cf. A228272. %K A228641 nonn %O A228641 1,1 %A A228641 _K. D. Bajpai_, Aug 28 2013