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A067075 a(n) is the smallest number m such that the sum of the digits of m^3 is equal to n^3. 9
0, 1, 2, 27, 1192, 341075, 3848163483, 2064403725539899 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,3
COMMENTS
If n = 6*k, a(n) <= A002283(n^3/18). For example, a(6) = 3848163483 <= A002283(6^3/18) = 999999999999. - Seiichi Manyama, Aug 12 2017
a(n) >= ceiling(A051885(n^3)^(1/3)). For example a(7) >= ceiling(A051885(7^3)^(1/3)) = ceiling((2*10^38-1)^(1/3)) = 5848035476426 - David A. Corneth, Aug 23 2018
From Zhining Yang, Jun 20 2024: (Start)
a(8) <= 99995999799995999999999.
a(9) <= 999699989999999949999999999999999.
a(10) <= 199999999929999999999949999999999999999999999.
(End)
LINKS
EXAMPLE
a(3) = 27 as 27^3 = 19683 is the smallest cube whose digit sum = 27 = 3^3.
MATHEMATICA
Do[k = 1; While[Plus @@ IntegerDigits[k^3] != n^3, k++ ]; Print[k], {n, 1, 6}] (* Ryan Propper, Jul 07 2005 *)
PROG
(PARI) a(n) = my(k=0); while (sumdigits(k^3) != n^3, k++); k; \\ Seiichi Manyama, Aug 12 2017
CROSSREFS
Cf. A051885, A061912, A067074. Subsequence of A067177.
Sequence in context: A078102 A221534 A221535 * A015217 A320417 A113094
KEYWORD
nonn,base,more
AUTHOR
Amarnath Murthy, Jan 05 2002
EXTENSIONS
Corrected and extended by Ryan Propper, Jul 07 2005
a(0)=0 prepended by Seiichi Manyama, Aug 12 2017
a(7) from Zhining Yang, Jun 20 2024
STATUS
approved

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Last modified July 24 22:37 EDT 2024. Contains 374585 sequences. (Running on oeis4.)