OFFSET
0,4
COMMENTS
EXAMPLE
a(3)=2, since f takes on exactly two distinct values 10 and 13: f({1,2,3})=10, f({1,3,2})=13, f({2,1,3})=13, f({2,3,1})=13, f({3,1,2})=13 and f({3,2,1})=10.
CROSSREFS
KEYWORD
nonn,more
AUTHOR
John W. Layman, Jul 31 2003
EXTENSIONS
a(0)=1 prepended and a(13)-a(28) added by Alois P. Heinz, Aug 24 2024
STATUS
approved