Re: [math-fun] n and n^3 have all digits odd

Quoth rcs@xmission.com

Cubes (mod 9) are always 0, 1, or 8. The low order ternary digits are 00, 01, or 22. --Rich

To settle the decimal case, you have to go up to mod 10^9 at which point you will discover that none of the 1000 possibilities is all odd digits. I did it by grepping the output of this program: #include <stdio.h> int main(){ for(int i=0;i!=1000;i++) printf("%09d\n", i*i*i); return 0; } -- Tom Duff. Seize you your paper and go into an art seminar!