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A361349
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Numbers k such that A361338(k) = 10.
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12
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17117, 17727, 17749, 18839, 19933, 21761, 22777, 29391, 30397, 31157, 31317, 31643, 33949, 34199, 35909, 39723, 39789, 39797, 39803, 39813, 42973, 44219, 44517, 46347, 47463, 49171, 49771, 49877, 53211, 53751, 57169, 57311, 57769, 57781, 57941, 57943, 57961, 59093
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OFFSET
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1,1
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LINKS
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PROG
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(Python)
from itertools import count, islice
from math import prod
c, d, m = {n}, set(), 0
while True:
c = set(prod(divmod(k, s)) for k in c for i in range(1, len(str(k))) if k%(s:=(r:=10**(i-1))*10)>=r or i==1)
d |= c
if (r:=len(d)) == m:
return sum(1 for q in d if q<10)
m = r
def A361349_gen(startvalue=1): # generator of terms >= startvalue
return filter(lambda n:A361338(n)==10, count(max(startvalue, 1)))
(Python)
from functools import lru_cache
from itertools import count, islice
@lru_cache(maxsize=None)
def f(n):
if n < 10: return {n}
s = str(n)
return {e for i in range(1, len(s)) if s[i]!="0" or i==len(s)-1 for e in f(int(s[:i])*int(s[i:]))}
def agen(): # generator of terms
yield from (k for k in count() if len(f(k)) == 10)
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CROSSREFS
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KEYWORD
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nonn,base
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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