OFFSET
1,3
COMMENTS
See full definition, its source and another example in A097151.
EXAMPLE
As the only digits permissible are in {-5,-4,-3,-2,-1,0,1,2,3,4}, 5 = 1*10 - 5 is the first number requiring two of these digits: 1,-5.
CROSSREFS
KEYWORD
base,easy,sign
AUTHOR
Rick L. Shepherd, Jul 27 2004
STATUS
approved