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 A229063 #27 Sep 22 2013 16:18:48 %S A229063 0,1,6,15,29,50,80,120,171,235,313,407,517,646,795,965,1158,1374,1616, %T A229063 1885,2182,2509,2867,3258,3682,4142,4639,5174,5748,6363,7021,7723, %U A229063 8470,9264,10105,10996,11939,12933,13981,15084,16244,17462,18739,20078,21478,22942 %N A229063 Volume of the Johnson square pyramid (rounded down) with all the edge lengths equal to n. %C A229063 Johnson square pyramid: Square base with four equilateral triangular-faces. All the edge lengths are equal to n. %H A229063 K. D. Bajpai, <a href="/A229063/b229063.txt">Table of n, a(n) for n = 1..1000</a> %H A229063 Wikipedia, <a href="http://en.wikipedia.org/wiki/Square_pyramid">Square pyramid</a> %F A229063 a(n) = floor(n^3*sqrt(2)/6) %e A229063 a(9)=171: Volume= sqrt(2)/6*n^3= sqrt(2)/6*9^3= 171.8269478 and floor(171.8269478)= 171. %p A229063 A229063 := proc(n) %p A229063 floor(n^3*sqrt(2)/6) ; %p A229063 end proc: %t A229063 Table[Floor[k^3*Sqrt[2]/6],{k,1,100}] %Y A229063 Cf. A228189. %K A229063 nonn %O A229063 1,3 %A A229063 _K. D. Bajpai_, Sep 17 2013