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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
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
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
KEYWORD
nonn,base
AUTHOR
Reiner Moewald, Mar 22 2015
STATUS
approved