cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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

Original entry on oeis.org

103, 1052, 1139, 2758, 26315, 206896, 1012658, 15789473, 137931034, 183673469, 3157894736, 421052631578, 1020408163265, 2105263157894, 13559322033898, 36842105263157, 241379310344827, 1525423728813559, 11392405063291139
Offset: 1

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Examples

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

Programs

  • Python
    from itertools import count, islice
    def A034180_gen(): # generator of terms
        for l in count(1):
            clist = []
            for k in range(1,10):
                a, b = 10**l-k, 10**(l-1)-k
                for m in range(1,10):
                    q, r = divmod(m*a-1,10*k-1)
                    if r == 0 and b <= q - k <= a:
                        clist.append(10*q+m)
            yield from sorted(clist)
    A034180_list = list(islice(A034180_gen(),20)) # Chai Wah Wu, Apr 23 2022

Extensions

Terms sorted and title clarified by Sean A. Irvine, Aug 04 2020
a(19) corrected by Chai Wah Wu, Apr 23 2022