OFFSET
0,3
COMMENTS
Indexing starts from zero, because a(0)=0 is a special case in this sequence. To get those n for which A060502(n) = 1, start listing terms from a(1) = 1 onward.
From n=1 onward numbers in whose factorial base representation (A007623) the difference i_x - d_x is the same for all nonzero digits d_x present. Here i_x is the position of digit d_x from the least significant end.
From n=1 onward also n such that A060498(n) is a one-ball juggling pattern.
LINKS
EXAMPLE
4 ("20" in factorial base) is present, because all nonzero digits are on the same slope as there is only one nonzero digit.
14 ("210" in factorial base) is present, because all nonzero digits are on the same slope, as 3-2 = 2-1.
19 ("301" in factorial base) is present, because all nonzero digits are on the same slope, as 3-3 = 1-1.
21 ("311" in factorial base) is NOT present, because not all of its nonzero digits are on the same slope, as 3-3 <> 2-1.
PROG
(Scheme, with Antti Karttunen's IntSeq-library)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Antti Karttunen, Aug 16 2016
STATUS
approved