

A115927


a(n) is the number of k such that k and n*k, taken together, are pandigital.


11



0, 48, 6, 8, 12, 0, 1, 16, 3, 0, 0, 1, 1, 6, 3, 1, 19, 6, 4, 12, 0, 3, 3, 4, 3, 9, 2, 1, 8, 2, 0, 16, 1, 3, 14, 0, 3, 7, 3, 4, 0, 3, 1, 13, 4, 1, 6, 0, 1, 12, 0, 2, 28, 1, 4, 6, 1, 3, 6, 3, 0, 28, 1, 1, 10, 1, 1, 4, 5, 7, 0, 3, 3, 11, 0, 2, 8, 1, 1, 46, 0, 0, 5, 3, 1, 7, 5, 6, 8, 3, 0, 13, 2, 3
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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[d1] = l[d] # Chai Wah Wu, May 24 2015


CROSSREFS

Cf. A054383, A115922, A115923, A115924, A115925, A114126.
Sequence in context: A037941 A229190 A069012 * A298619 A298831 A087407
Adjacent sequences: A115924 A115925 A115926 * A115928 A115929 A115930


KEYWORD

nonn,base


AUTHOR

Giovanni Resta, Feb 06 2006


STATUS

approved



