A115927 a(n) is the number of k such that k and n*k, taken together, are pandigital.

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

Offset: 1

Author

Giovanni Resta, Feb 06 2006

Keywords

• nonn
• base

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

Examples

			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.
		

Links

• Chai Wah Wu, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A054383, A115922, A115923, A115924, A115925, A114126.

Programs

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