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A167620
Numbers that are multiples of their digital product, where this digital product also appears as their least significant digits.
1
1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 12, 15, 111, 112, 115, 315, 612, 1111, 1112, 1113, 1115, 1116, 11111, 11112, 11115, 12312, 13212, 21312, 23112, 31212, 32112, 111111, 111112, 111115, 111315, 111612, 113115, 116112, 131115, 161112, 311115, 511175
OFFSET
1,2
COMMENTS
Subsequence of A007602. - R. J. Mathar, Nov 12 2009
The digital products of the terms are a subsequence of A238985. - Karl-Heinz Hofmann, Feb 16 2024
LINKS
Karl-Heinz Hofmann, Table of n, a(n) for n = 1..8042 (Terms < 10^18, first 690 terms from David A. Corneth)
EXAMPLE
612 is in the list because 6*1*2=12, 612 is a multiple of 12, and 12 is the final two digits of 612.
PROG
(PARI) is(n) = { my(vp = vecprod(digits(n))); vp != 0 && n %vp == 0 && n % 10^(#digits(vp)) == vp } \\ David A. Corneth, Mar 30 2021
(Python)
A167620 = []
for k in range(1, 511176):
dprod, k_str = 1, str(k)
for d in range(0, len(k_str)): dprod *= int(k_str[d])
if dprod != 0 and k % dprod == 0 and str(dprod) == k_str[-(len(str(dprod))):]:
A167620.append(k)
print(A167620) # Karl-Heinz Hofmann, Jan 26 2024
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Claudio Meller, Nov 07 2009
STATUS
approved