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A252664 Minimal nontrivial undulant (A046075) divisible by n, or 0 if no undulant is divisible by n. 2
101, 202, 141, 212, 505, 252, 161, 232, 171, 1010, 121, 252, 494, 252, 525, 272, 272, 252, 171, 2020, 252, 242, 161, 696, 525, 494, 2727, 252, 232, 3030, 434, 3232, 363, 272, 525, 252, 3737, 494, 585, 4040, 656, 252, 989, 484, 585, 414, 141, 4848, 343, 5050 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Undulants are numbers are of the form ababab..... with a and b distinct digits (base 10, a nonzero). An undulate is nontrivial if it has at least 3 digits. - Danny Rorabaugh, Apr 22 2015

LINKS

Reiner Moewald, Table of n, a(n) for n = 1..499

EXAMPLE

505 is the least entry of A046075 that is divisible by 5, so a(5) = 505. Since an undulant cannot end in 00, a(100)=0. - Danny Rorabaugh, Apr 22 2015

PROG

(Python)

feld = []

for n in range(3, 500):

...for a in range(1, 10):

......for b in range(10):

.........if a != b:

............z_string = ""

............for pos in range(n):

...............if pos % 2 == 0:

..................z_string = z_string + str(a)

...............else:

..................z_string = z_string + str(b)

............z = int(z_string)

............feld.append(z)

feld_length = len(feld)

for z in range (1, 150):

...start = 0

...while start < feld_length and feld[start] % z != 0:

......start = start + 1

...if start < feld_length:

......print(z, feld[start])

CROSSREFS

Cf. A046075.

Sequence in context: A044714 A158128 A162670 * A134970 A081365 A138131

Adjacent sequences:  A252661 A252662 A252663 * A252665 A252666 A252667

KEYWORD

nonn,base

AUTHOR

Reiner Moewald, Mar 22 2015

STATUS

approved

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Last modified February 26 12:43 EST 2020. Contains 332280 sequences. (Running on oeis4.)