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 A120142 #15 May 13 2023 19:20:50
%S A120142 16,24,36,54,81,121,182,273,409,614,921,1381,2072,3108,4662,6993,
%T A120142 10489,15734,23601,35401,53102,79653,119479,179219,268828,403242,
%U A120142 604863,907295,1360942,2041413,3062120,4593180,6889770,10334655,15501982
%N A120142 a(n) = 16 + floor(Sum_{j=1..n-1} a(j)/2).
%H A120142 G. C. Greubel, <a href="/A120142/b120142.txt">Table of n, a(n) for n = 1..1000</a>
%t A120142 Nest[Append[#,16+Floor[Total[#]/2]]&,{16},40] (* _Harvey P. Dale_, Apr 20 2011 *)
%o A120142 (SageMath)
%o A120142 @CachedFunction
%o A120142 def A120142(n): return 16 + (sum(A120142(k) for k in range(1,n)))//2
%o A120142 [A120142(n) for n in range(1,60)] # _G. C. Greubel_, May 11 2023
%Y A120142 Cf. A073941, A072493, A112088, A120134 - A120141, A120143 - A120209.
%K A120142 nonn
%O A120142 1,1
%A A120142 _Graeme McRae_, Jun 10 2006