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A222810 Number of n-digit numbers N with distinct digits such that the reversal of N divides N. 7
9, 9, 3, 5, 3, 2, 0, 0, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Suggested by A214927.

a(n)=0 for all n > 6.

LINKS

Table of n, a(n) for n=1..9.

EXAMPLE

Solutions with 1 through 6 digits:

[1, 2, 3, 4, 5, 6, 7, 8, 9],

[10, 20, 30, 40, 50, 60, 70, 80, 90],

[510, 540, 810],

[5610, 5940, 8712, 8910, 9801],

[65340, 87120, 87912],

[659340, 879120],

PROG

(Python)

import collections

col = []

count = 0

for n in range(0, 9):

....a = 10**n

....stop = 10**(n+1)

....while a < stop:

........b = str(a)

........c = list(b)

........d = c[::-1]

........e = int("".join(c))

........f = int("".join(d))

........counter = collections.Counter(c)

........if e % f == 0 and counter.most_common(1)[0][1] == 1:

............count += 1

............col.append(a)

........a += 1

....print(n+1, " digits: ", count, " elements: ", col)

....count = 0

....col = []

# David Consiglio, Jr., Dec 04 2014

CROSSREFS

Cf. A214927, A222809, A222811, A222812.

For the actual numbers see A223080.

Sequence in context: A074879 A291366 A146490 * A140416 A226204 A296454

Adjacent sequences:  A222807 A222808 A222809 * A222811 A222812 A222813

KEYWORD

nonn,base

AUTHOR

N. J. A. Sloane, Mar 10 2013

EXTENSIONS

a(8)-a(9) from David Consiglio, Jr., Dec 04 2014

STATUS

approved

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Last modified December 5 22:37 EST 2019. Contains 329782 sequences. (Running on oeis4.)