OFFSET
1,1
COMMENTS
See A261913 for definition.
In the Friedman Problem of the Month page, there is a statement by John Hoffman which, if I have interpreted it correctly, asserts that this sequence has only a finite number of terms. However, Chai Wah Wu has extended the sequence out to 10^8, finding 481384 terms, the last one being a(481384) = 99998180. This sequence does not appear to be finite.
The first terms of this sequence are just beyond A109326(5). It can be expected that at least beyond A109326(6) = 1000101024 there will be examples where N-prevpal(N) and N-prevpal(prevpal(N)) are both of order 5; these numbers could be termed to be of order 6, and so on. - M. F. Hasler, Sep 13 2015
LINKS
Chai Wah Wu, Table of n, a(n) for n = 1..2278
Erich Friedman, Problem of the Month (June 1999)
M. F. Hasler, Sum of palindromes, OEIS wiki, Sep 10 2015
Chai Wah Wu, Table of n, a(n) for n = 1..481384 (zipped file)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
N. J. A. Sloane, Sep 10 2015
EXTENSIONS
More terms from Chai Wah Wu, Sep 11 2015 and Sep 12 2015
STATUS
approved