OFFSET
0,14
COMMENTS
Let the decimal expansion of n be abcd...efg, say. Then a(n) has decimal expansion |a-b| |b-c| |c-d| ... |e-f| |f-g|. Leading zeros in a(n) are omitted.
From M. F. Hasler, Nov 09 2019: (Start)
This sequence coincides with A080465 up to a(109) but is thereafter completely different.
LINKS
T. D. Noe, Table of n, a(n) for n = 0..10000
E. Angelini, The Ghost Iteration, Personal blog "Cinquante signes", Nov 2019
FORMULA
a(n) = 0 iff n is a repdigit >= 11 (A010785). - Bernard Schott, May 09 2022
EXAMPLE
a(371) = 46, for example.
a(110) = 01 = 1, while A080465(110) = 10 - 1 = 9. - M. F. Hasler, Nov 09 2019
MATHEMATICA
Table[FromDigits[Abs[Differences[IntegerDigits[n]]]], {n, 110}] (* Harvey P. Dale, Dec 16 2021 *)
PROG
(PARI) apply( A040115(n)=fromdigits(abs((n=digits(n+!n))[^-1]-n[^1])), [10..199]) \\ Works for all n >= 0. - M. F. Hasler, Nov 09 2019
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
EXTENSIONS
Definition clarified by N. J. A. Sloane, Aug 19 2008
Name edited by M. F. Hasler, Nov 09 2019
Terms a(0) = a(1) = ... = a(9) = 0 prepended by Max Alekseyev, Jul 26 2024
STATUS
approved