The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 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 (list; graph; refs; listen; history; text; internal format)
 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 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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified September 23 02:41 EDT 2021. Contains 347609 sequences. (Running on oeis4.)