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 A058261 #5 Jan 28 2014 08:46:17 %S A058261 0,2,21,8,25,48,112,24,171,60,154,108,117,238,255,64,204,360,380,140, %T A058261 147,330,345,240,575,260,2997,504,522,540,3286,160,858,442,455,756, %U A058261 777,798,1326,320,4469,336,1247 %N A058261 a(n) = n times the Collatz number of n (as given in A006577). %F A058261 a(n) = n*Collatz(n) %e A058261 a(4)=8 because the Collatz number of 4 is 2 (4 -> 2 -> 1) and then 8=4*2. %K A058261 nonn %O A058261 0,2 %A A058261 Felix Goldberg (felixg(AT)tx.technion.ac.il), Dec 17 2000