OFFSET
0,2
EXAMPLE
a(6)=105 since 105 + 6 = 111 and 105 - 6 = 99 both are palindromes and 105 is the least unused natural number for which this is true.
a(34)=a(58)=a(69)=0 since no unused natural numbers exist.
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Amarnath Murthy, Dec 04 2004
EXTENSIONS
Edited, corrected and extended by Mark Hudson (mrmarkhudson(AT)hotmail.com) and Ray Chandler, Dec 06 2004
STATUS
approved