

A229686


The negative number of minimum absolute value not obtainable from 1 in n steps using addition, multiplication, and subtraction.


1



1, 2, 4, 9, 29, 85, 311, 1549, 9851, 74587, 956633
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OFFSET

0,2


COMMENTS

This is similar to A141414 but applied to negative numbers. It is the greatest negative number that requires an n step SLP (Stright Line Program) to compute it.


LINKS

Table of n, a(n) for n=0..10.


EXAMPLE

For n=1 the value is 1 since 1 requires 2 steps SLP: 1,2,1.
For n=2 the value is 2 since 2 requires 3 steps SLP: 1,2,3,2.
For n=3 the value is 4 since 3 also requires only 3 steps but 4 requires 4: 1,2,4,5,4.


CROSSREFS

Cf. A141414, A216999, A214872.
Sequence in context: A241404 A005095 A300491 * A208965 A306505 A243789
Adjacent sequences: A229683 A229684 A229685 * A229687 A229688 A229689


KEYWORD

sign,hard


AUTHOR

Gil Dogon, Sep 27 2013


STATUS

approved



