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 A026869 #4 Mar 30 2012 18:56:11 %S A026869 1,1,4,5,17,23,74,104,326,468,1447,2104,6459,9466,28968,42658,130473, %T A026869 192656,589993,872290,2678007,3960318,12199689,18032179,55769978, %U A026869 82346931,255807384,377172666,1177155945,1732702830 %N A026869 a(n) = T(n,m) + T(n,m+1) + ... + T(n,n), m=[ (n+1)/2 ], T given by A026747. %K A026869 nonn %O A026869 0,3 %A A026869 _Clark Kimberling_