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A115927 a(n) is the number of k such that k and n*k, taken together, are pandigital. 11

%I

%S 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,

%T 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,

%U 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

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

%C 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

%H Chai Wah Wu, <a href="/A115927/b115927.txt">Table of n, a(n) for n = 1..10000</a>

%e a(7)=1 since there is only one number, k=14076, such that k and 7*k=98532.

%e a(9)=3 since there are 3 such numbers: 10638, 10647 and 10836.

%o (Python)

%o from itertools import permutations

%o l = {}

%o for d in permutations('0123456789', 10):

%o ....if d[0] != '0':

%o ........for i in range(9):

%o ............if d[i+1] != '0':

%o ................q, r = divmod(int(''.join(d[:i+1])),int(''.join(d[i+1:])))

%o ................if not r:

%o ....................if q in l:

%o ........................l[q] += 1

%o ....................else:

%o ........................l[q] = 1

%o A115927_list = [0]*max(l)

%o for d in l:

%o ....A115927_list[d-1] = l[d] # _Chai Wah Wu_, May 24 2015

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

%K nonn,base

%O 1,2

%A _Giovanni Resta_, Feb 06 2006

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Last modified December 8 01:46 EST 2019. Contains 329850 sequences. (Running on oeis4.)