A008928 Number of increasing sequences of addition chain type with maximal element n.

1, 1, 1, 2, 3, 6, 10, 21, 38, 77, 144, 293, 563, 1131, 2205, 4434, 8711, 17466, 34506, 69169, 137247, 274677, 546081, 1093217, 2177556, 4356756, 8688370, 17381926, 34691608, 69394626, 138578144, 277197191, 553794526, 1107654097, 2213527055, 4427345544, 8849519773

Offset: 1

Author

Mauro Torelli (torelli(AT)hermes.mc.dsi.unimi.it)

Keywords

• nonn

Comments

This sequence counts all addition chains for n. - David W. Wilson, Apr 01 2006

In other words, a(n) = the number of increasing addition chains ending in n. - Don Reble, Apr 09 2006

Links

• Martin Fuller, Table of n, a(n) for n = 1..64
• Don Reble, Python program
• Mauro Torelli, Increasing integer sequences and Goldbach's conjecture, RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications, 40:2 (2006), pp. 107-121.

Crossrefs

Cf. A008927, A079301, A008933.

Extensions

More terms from David W. Wilson, Apr 01 2006

More terms from Don Reble, Apr 09 2006