|
| |
|
|
A140361
|
|
Number of additions, subtractions, or multiplications necessary to reach n starting from 1 and 2.
|
|
1
| |
|
|
0, 0, 1, 1, 2, 2, 3, 2, 2, 3, 3, 3, 4, 3, 3, 2, 3, 3, 4, 3, 4, 4, 4, 4, 3, 4, 3, 4, 4, 4, 4, 3, 4, 4, 4, 3, 4, 4, 4, 4, 5, 4, 5, 5, 4, 5, 5, 4, 4, 4, 5, 5, 5, 4, 5, 4, 5, 5, 5, 4, 5, 4, 4, 3, 4, 4, 5, 4, 5, 5, 5, 4, 5, 5, 4, 5, 5, 4, 4, 4, 3, 4, 4, 4, 5, 5, 5, 5, 5, 4, 5, 5, 5, 5, 5, 5, 5, 5, 4
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,5
|
|
|
COMMENTS
| tau(n) is the name of the function given in the Koiran article, it has no relation to the divisor function. [From Leonid Broukhis (leob(AT)mailcom.com), Aug 04 2008]
|
|
|
LINKS
| P. Koiran, Valiant's Model and the Cost of Computing Integers, Comput. Complex. 13 (2004), pp. 131-146.
|
|
|
EXAMPLE
| tau(7) = 3 because we 7 = (2 + 1) + (2 * 2), or 7 = 2 * (2 + 2) - 1 and there is no shorter way.
|
|
|
CROSSREFS
| Cf. A173419.
Sequence in context: A084126 A135975 A136032 * A187182 A176208 A153095
Adjacent sequences: A140358 A140359 A140360 * A140362 A140363 A140364
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| Leonid Broukhis (leob(AT)mailcom.com), Jul 21 2008
|
|
|
EXTENSIONS
| So this is tau( ) applied to which sequence? - N. J. A. Sloane (njas(AT)research.att.com), Jul 24 2008
Corrected, from 6 to 5, a(59) = ((2+2)*2)*8-1-4 and a(94) = (((2+2)+2)+4)*10-6 Leonid Broukhis (leob(AT)mailcom.com), Aug 04 2008
|
| |
|
|
