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A034180 Numbers m with property that rotating digits of m right gives k*m + 1 for some k >= 1. 2

%I #21 Apr 23 2022 16:07:44

%S 103,1052,1139,2758,26315,206896,1012658,15789473,137931034,183673469,

%T 3157894736,421052631578,1020408163265,2105263157894,13559322033898,

%U 36842105263157,241379310344827,1525423728813559,11392405063291139

%N Numbers m with property that rotating digits of m right gives k*m + 1 for some k >= 1.

%H Chai Wah Wu, <a href="/A034180/b034180.txt">Table of n, a(n) for n = 1..958</a>

%e Rotating 103 gives 310 and 310 = 3 * 103 + 1. - _Sean A. Irvine_, Aug 04 2020

%o (Python)

%o from itertools import count, islice

%o def A034180_gen(): # generator of terms

%o for l in count(1):

%o clist = []

%o for k in range(1,10):

%o a, b = 10**l-k, 10**(l-1)-k

%o for m in range(1,10):

%o q, r = divmod(m*a-1,10*k-1)

%o if r == 0 and b <= q - k <= a:

%o clist.append(10*q+m)

%o yield from sorted(clist)

%o A034180_list = list(islice(A034180_gen(),20)) # _Chai Wah Wu_, Apr 23 2022

%K nonn,base

%O 1,1

%A _Erich Friedman_

%E Terms sorted and title clarified by _Sean A. Irvine_, Aug 04 2020

%E a(19) corrected by _Chai Wah Wu_, Apr 23 2022

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Last modified April 19 10:56 EDT 2024. Contains 371791 sequences. (Running on oeis4.)