OFFSET
1,1
COMMENTS
The unique solutions are in A189482. Ufnarovski and Ahlander list these numbers on page 7 of their paper.
Interestingly, for about half the numbers n in this sequence, the unique solution is x = 2(n-2) because n-2 is prime.
REFERENCES
See A003415.
LINKS
T. D. Noe, Table of n, a(n) for n = 1..5000
Victor Ufnarovski and Bo Ahlander, How to Differentiate a Number, J. Integer Seqs., Vol. 6, 2003.
FORMULA
n such that A099302(n) = 1.
CROSSREFS
KEYWORD
nonn
AUTHOR
T. D. Noe, Apr 22 2011
STATUS
approved