正整数中: 使得十进制表示的非零子序列不能被 3 整除。
1, 2, 4, 5, 7, 8, 10, 11, 14, 17, 20, 22, 25, 28, 40, 41, 44, 47, 50, 52, 55, 58, 70, 71,
74, 77, 80, 82, 85, 88, 100, 101, 104, 107, 110, 140, 170, 200, 202, 205, 208, 220,
250, 280, 400, 401, 404, 407, 410, 440, 470, 500, 502, 505, 508, 520, 550, 580,....
s=1+1/2+1/4+1/5+1/7+1/8+1/10+1/11+1/14+1/17+1/20+1/22+1/25+........ |