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 A138847 #5 Jul 28 2023 12:25:57
%S A138847 1,3,7,15,20,23,29,41,65,82,93,100,114,123,141,177,202,251,284,349,
%T A138847 392,478,535,574,652,805,910,1113,1248,1518,1703,1826,2072,2241,2570,
%U A138847 2789,2948,3243,3812,4191,4474,4979,5356,5607,5774,5885,6107
%N A138847 Row sums of a Collatz triangle.
%F A138847 a(n) = Sum_{k=0..n} A092892(k).
%F A138847 a(n) = Sum_{k=0..n} A138895(n,k).
%Y A138847 Partial sums of A092892.
%Y A138847 Row sums of A138895.
%K A138847 easy,nonn
%O A138847 0,2
%A A138847 _Paul Barry_, Mar 31 2008, Apr 02 2008