Offset default value

[N. J. A. Sloane]

J.S. said:

%O = Offset a, b :

*    a is subscript of first term
*    b gives position of first entry greater than or equal to 2 in magnitude
(or 1 if no such entry exists)

But why is 1 the default value of b? Wouldn't 0 or even -1 be better? After
all, the value b = 1 can appear in the usual, non-default case.

Me:  no, this reveals that once again I have failed 
to convey the meaning of the second offset!

examples:

1 2 3 4 5 6...   b=2

2 3 4 5 6 7 ...  b=1

10 20 30 ...     b=1

0 0 0 -1 1 1 2 3 4 ... b=7

start with first term, which is term ONE. move right
until
you reach a term with absolute value > 1.
it's position is b

by definition b >= 1, therefore, and b = 1 is the commonest value.

Neil