A095048 - OEIS (original) (raw)

1, 2, 2, 3, 2, 4, 2, 4, 3, 4, 1, 5, 2, 4, 3, 5, 2, 6, 2, 5, 4, 2, 3, 6, 3, 4, 5, 5, 3, 6, 2, 6, 2, 5, 4, 7, 3, 5, 3, 6, 2, 6, 3, 3, 5, 5, 3, 6, 4, 4, 4, 6, 3, 9, 2, 7, 5, 5, 3, 7, 2, 4, 6, 6, 4, 4, 3, 7, 5, 7, 2, 8, 3, 5, 5, 8, 2, 7, 3, 7, 6, 4, 3, 7, 4, 6, 6, 4, 3, 9, 4, 6, 3, 5, 3, 7, 3, 6, 3, 5, 2, 8

COMMENTS

a(n) <= 10, a(A095050(n)) = 10.

Almost all (in the sense of natural density) terms of this sequence are equal to 10. - Charles R Greathouse IV, Nov 16 2022

EXAMPLE

Set of divisors of n=10: {1,2,5,10}, therefore a(10) = #{0,1,2,5} = 4.

Set of divisors of n=16: {1,2,4,8,16}, therefore a(16)=#{1,2,4,6,8} = 5.

MAPLE

local digset ;

digset := {} ;

for d in numtheory[divisors](n) do

digset := digset union convert(convert(d, base, 10), set) ;

end do:

nops(digset) ;

end proc:

PROG

(Haskell)

import Data.List (group, sort)

a095048 = length . group . sort . concatMap show . a027750_row

(Python)

from sympy import divisors

def a(n):

s = set("1"+str(n))

if len(s) == 10: return 10

for d in divisors(n, generator=True):

s |= set(str(d))

if len(s) == 10: return 10

return len(s)

(PARI) a(n) = my(d = divisors(n), s = 0); for(i = 1, #d, v = digits(d[i]); for(j = 1, #v, s = bitor(s, 1<<v[j]); if(s == 1023, return(10)))); hammingweight(s) \\ David A. Corneth, Nov 16 2022