OFFSET
0,11
COMMENTS
LINKS
David A. Corneth, Table of n, a(n) for n = 0..10000
EXAMPLE
n = 10: products of digits are {0, 1, 0*1}, distinct products of digits are {0, 1}, thus a(10) = 2.
n = 11: products of digits are {1, 1*1}, distinct product of digits is {1}, thus a(11) = 1.
n = 23: products of digits are {2, 3, 2*3}, distinct products of digits are {2, 3, 6}, thus a(23) = 3.
PROG
(PARI) a(n) = {if(n==0, return(1));
my(d = vecsort(digits(n)), l = List());
for(i = 1, #d,
forvec(x = vector(i, j, [1, #d]),
c = vecprod(vector(i, j, d[x[j]]));
listput(l, c)
,
2
)
);
#Set(l)
} \\ David A. Corneth, Mar 05 2024
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Ctibor O. Zizka, Jul 10 2023
STATUS
approved