OFFSET
1,1
COMMENTS
The sequence of cubes starts: 29791, 32768, 1157625, 1367631, 2097152, 2197000, 3307949, 4657463, ...
LINKS
Lars Blomberg, Table of n, a(n) for n = 1..10000
Jeremy Gardiner, Middle digit in cube numbers, Seqfan Mailing list, Dec 12 2016.
EXAMPLE
31^3 = 29(7)91, 191^3 = 696(7)871, 619^3 = 2371(7)6659.
MATHEMATICA
Select[Range[865], OddQ[len=Length[IntegerDigits[#^3]]]&&Part[IntegerDigits[#^3], (len+1)/2]==7 &] (* Stefano Spezia, Oct 03 2023 *)
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
Lars Blomberg, Jan 07 2017
STATUS
approved