

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



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



KEYWORD

sign,hard


AUTHOR



STATUS

approved



