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 A049697 #12 May 13 2013 01:47:54
%S A049697 1,3,6,10,16,22,30,40,50,60,74,88,104,122,136,152,176,198,222,248,268,
%T A049697 290,322,352,380,412,442,472,512,548,586,632,668,704,744,780,828,882,
%U A049697 924,964,1020,1072,1126
%N A049697 a(n)=T(n,n+1), array T as in A049695.
%F A049697 a(n-1)=sum_{k=1...n}mu(k)floor(n/k)ceiling(n/k); a(n) is asymptotic to (6/Pi^2)*n^2 - _Benoit Cloitre_, Jun 27 2005
%o A049697 (PARI) a(n)=sum(k=1,n++,n\k*moebius(k)*ceil(n/k)) \\ _Charles R Greathouse IV_, Mar 02 2012
%Y A049697 Cf. A018805.
%K A049697 nonn
%O A049697 0,2
%A A049697 _Clark Kimberling_