OFFSET
1,2
COMMENTS
There are 1549586 nonzero terms in a(n). The largest n for which a(n) > 0 is 987654320. The largest a(n) is a(2) = 48. - Chai Wah Wu, May 24 2015
LINKS
Chai Wah Wu, Table of n, a(n) for n = 1..10000
EXAMPLE
a(7)=1 since there is only one number, k=14076, such that k and 7*k=98532.
a(9)=3 since there are 3 such numbers: 10638, 10647 and 10836.
PROG
(Python)
from itertools import permutations
l = {}
for d in permutations('0123456789', 10):
....if d[0] != '0':
........for i in range(9):
............if d[i+1] != '0':
................q, r = divmod(int(''.join(d[:i+1])), int(''.join(d[i+1:])))
................if not r:
....................if q in l:
........................l[q] += 1
....................else:
........................l[q] = 1
A115927_list = [0]*max(l)
for d in l:
....A115927_list[d-1] = l[d] # Chai Wah Wu, May 24 2015
KEYWORD
nonn,base
AUTHOR
Giovanni Resta, Feb 06 2006
STATUS
approved