OFFSET
0,3
COMMENTS
Nonnegative integer n is included here iff the number of distinct nonzero digits elements present in its factorial base representation is equal to the number of distinct elements in a multiset [(i_x - d_x) | where d_x ranges over each (not all necessarily distinct) nonzero digit present and i_x is that digit's position from the right].
LINKS
EXAMPLE
11 ("121" in factorial base) is included, as there are two occupied slopes (3-1 = 2 and 2-2 = 1-1 = 0) and also two distinct nonzero digits, namely 1 and 2.
59 ("2121" in factorial base) is included, as there are two occupied slopes (4-2 = 3-1 and 2-2 = 1-1) and also two distinct nonzero digits, namely 1 and 2.
226 ("14120") is included, as there are three occupied slopes (5-1 = 4, 4-4 = 2-2 = 0, 3-1 = 2) and also three distinct nonzero digits, 1, 2 and 4.
PROG
(Scheme, with Antti Karttunen's IntSeq-library)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Antti Karttunen, Aug 16 2016
STATUS
approved