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A122352
Knuth's power tree represented by parent node number.
2
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, 14, 28, 15, 28, 16, 17, 17, 21, 18, 36, 19, 26, 20, 40, 21, 40, 22, 30, 23, 42, 24, 48, 25, 48, 26, 52, 27, 44, 28, 38, 29, 31, 30, 56, 31, 42, 32, 64, 33, 66, 34, 46, 35, 57, 36, 37, 37
OFFSET
1,3
COMMENTS
This method of representing the power tree is suggested by exercise 10 in Section 4.6.3 page 481 TAOCP Vol. 2.
REFERENCES
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.
LINKS
Hugo Pfoertner, Addition chains
EXAMPLE
The power tree sequence for 54 is 1,2,3,6,9,18,27,54, so a(54) = 27.
CROSSREFS
Cf. A114622.
Sequence in context: A300271 A252461 A323608 * A338903 A362830 A248519
KEYWORD
nonn
AUTHOR
STATUS
approved