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 A048115 #7 Jun 26 2025 12:18:41
%S A048115 1,1,2,4,6,12,24,42,84,168,312,624,1248,2388,4776,9552,18576,37152,
%T A048115 74304,145884,291768,583536,1152456,2304912,4609824,9138888,18277776,
%U A048115 36555552,72654552,145309104,290618208,578607912
%N A048115 (1/2)*Sum{T(n,i): i=0,1,...,n}, where T is given by A048113.
%Y A048115 Cf. A048113.
%K A048115 nonn
%O A048115 3,3
%A A048115 _Clark Kimberling_