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 A122352 #8 Jul 20 2013 18:35:11 %S A122352 0,1,2,2,3,3,5,4,6,5,10,6,10,7,10,8,16,9,14,10,14,11,13,12,15,13,18, %T A122352 14,28,15,28,16,17,17,21,18,36,19,26,20,40,21,40,22,30,23,42,24,48,25, %U A122352 48,26,52,27,44,28,38,29,31,30,56,31,42,32,64,33,66,34,46,35,57,36,37,37 %N A122352 Knuth's power tree represented by parent node number. %C A122352 This method of representing the power tree is suggested by exercise 10 in Section 4.6.3 page 481 TAOCP Vol. 2. %D A122352 D. E. Knuth, The Art of Computer Programming Third Edition. Vol. 2, Seminumerical Algorithms. Chapter 4.6.3 Evaluation of Powers, Page 464. Addison-Wesley, Reading, MA, 1997. %H A122352 Alois P. Heinz, <a href="/A122352/b122352.txt">Table of n, a(n) for n = 1..10000</a> %H A122352 Hugo Pfoertner, <a href="/A003313/a003313.txt">Addition chains</a> %e A122352 The power tree sequence for 54 is 1,2,3,6,9,18,27,54, so a(54) = 27. %Y A122352 Cf. A114622. %K A122352 nonn %O A122352 1,3 %A A122352 _Franklin T. Adams-Watters_, Aug 30 2006