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.

A359698 Least k > 0 such that the first n digits of 2^k and 3^k are identical.

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%I A359698 #57 Jun 04 2023 08:56:10
%S A359698 1,17,193,619,2016,91958,91958,8186278,45392361,977982331,26450915298,
%T A359698 91600221212,196425900073,14810317269038,44430951807114,
%U A359698 626642721222487,626642721222487,102882886570917135,874191214492184404,3830977578643912683,86801197487071715103
%N A359698 Least k > 0 such that the first n digits of 2^k and 3^k are identical.
%H A359698 Zhao Hui Du, <a href="/A359698/b359698.txt">Table of n, a(n) for n = 0..1000</a>
%e A359698    n    k = a(n)   1st n digits
%e A359698   --  -----------  -------------
%e A359698    0            1
%e A359698    1           17  1...
%e A359698    2          193  12...
%e A359698    3          619  217...
%e A359698    4         2016  7524...
%e A359698    5        91958  13071...
%e A359698    6        91958  130719...
%e A359698    7      8186278  1701547...
%e A359698    8     45392361  17179395...
%e A359698    9    977982331  725070476...
%e A359698   10  26450915298  2919267309...
%e A359698 a(3) = 619 because 2^619 = 2.175...*10^186 and 3^619 = 2.177...*10^295 both begin with the same three digits (in base ten), and this is not true of any smaller positive integer than 619.
%e A359698 a(0) = 1 because 2^1 and 3^1 share zero leading digits.
%Y A359698 Cf. A000079, A000244, A088995.
%K A359698 base,nonn
%O A359698 0,2
%A A359698 _Keith F. Lynch_, May 20 2023
%E A359698 a(11)-a(20) from _Jon E. Schoenfield_, May 21 2023