A364136 a(n) is the number of distinct products of nonempty submultisets of the digits of n.
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 2, 2, 3, 2, 3, 3, 3, 3, 3, 3, 2, 2, 3, 3, 2, 3, 3, 3, 3, 3, 2, 2, 3, 3, 3, 2, 3, 3, 3, 3, 2, 2, 3, 3, 3, 3, 2, 3, 3, 3, 2, 2, 3, 3, 3, 3, 3, 2, 3, 3, 2, 2, 3, 3, 3, 3, 3, 3, 2, 3, 2
Offset: 0
Examples
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.
Links
- David A. Corneth, Table of n, a(n) for n = 0..10000
Programs
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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
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