|
|
A292856
|
|
Numbers n such that 7 applications of 'Reverse and Subtract' lead to n, whereas fewer than 7 applications do not lead to n.
|
|
10
|
|
|
142710354353443018141857289645646556981858, 236547461211163745741763452538788836254258, 331948602685207939133668051397314792060866, 336111694728585211732663888305271414788267
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
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
|
|
|
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
|
Cf. A072142, A072143, A072718, A072719, A215669, A292634, A292635, A292846, A292857, A292858, A292859.
|
|
KEYWORD
|
nonn,base
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|