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 A280644 Numbers k such that k^3 has an odd number of digits and the middle digit is 4. 3

%I

%S 7,104,112,140,143,158,166,186,188,195,465,467,490,541,558,572,595,

%T 598,604,605,606,607,613,616,622,625,630,634,635,640,643,647,653,667,

%U 675,679,687,702,712,718,720,727,734,738,759,764,783,787,802,810,815,818

%N Numbers k such that k^3 has an odd number of digits and the middle digit is 4.

%C The sequence of cubes starts: 343, 1124864, 1404928, 2744000, 2924207, 3944312, 4574296, 6434856, ...

%H Lars Blomberg, <a href="/A280644/b280644.txt">Table of n, a(n) for n = 1..10000</a>

%H Jeremy Gardiner, <a href="http://list.seqfan.eu/pipermail/seqfan/2016-December/017135.html">Middle digit in cube numbers</a>, Seqfan Mailing list, Dec 12 2016.

%e 7^3 = 3(4)3, 195^3 = 741(4)875, 640^3 = 2621(4)4000

%Y Cf. A280640-A280643, A280645-A280649, A181354.

%Y See A279420-A279429 for a k^2 version.

%Y See A279430-A279431 for a k^2 version in base 2.

%K nonn,base,easy

%O 1,1

%A _Lars Blomberg_, Jan 07 2017

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Last modified May 12 04:27 EDT 2021. Contains 343810 sequences. (Running on oeis4.)