OFFSET
1,1
COMMENTS
There are 7 forty-two-digit terms in the sequence. Terms of derived sequences can be obtained either by inserting at the center of their digits any number of 9's or by concatenating a term any number of times with itself and inserting an equal number of 0's at all junctures.
LINKS
Ray Chandler, Table of n, a(n) for n = 1..7
J. H. E. Cohn, Palindromic differences, Fibonacci Quart. 28 (1990), no. 2, 113-120.
FORMULA
n = f^7(n), n <> f^k(n) for k < 7, where f: x -> |x - reverse(x)|.
EXAMPLE
142710354353443018141857289645646556981858 -> 715479301293103964616284520698706896035383 -> 331948602685207939133668051397314792060866 -> 336111694728585211732663888305271414788267 -> 426775719443918676633573224280556081323366 -> 236547461211163745741763452538788836254258 -> 615905177676671508625384094822323328491374 -> 142710354353443018141857289645646556981858
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Meritxell Vila Miñana, Sep 25 2017
EXTENSIONS
Terms ordered by Ray Chandler, Sep 27 2017
STATUS
approved