要找出哪两个质数和为241,需要从小于241的所有质数中进行排列组合,直到找到两个质数相加得到241为止。
可以先写出小于241的所有质数:
2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,97,101,103,107,109,113,127,131,137,139,149,151,157,163,167,173,179,181,191,193,197,199,211,223,227,229,233,239
接下来,从最小的两个质数开始配对相加,依次向上组合,直到找到两个相加等于241的质数。
2 + 239 = 241
3 + 238 = 241
5 + 236 = 241
7 + 234 = 241
11 + 230 = 241
13 + 228 = 241
17 + 224 = 241
19 + 222 = 241
23 + 218 = 241
29 + 212 = 241
31 + 210 = 241
37 + 204 = 241
41 + 200 = 241
43 + 198 = 241
47 + 194 = 241
53 + 188 = 241
59 + 182 = 241
61 + 180 = 241
67 + 174 = 241
71 + 170 = 241
73 + 168 = 241
79 + 162 = 241
83 + 158 = 241
89 + 152 = 241
97 + 144 = 241
101 + 140 = 241
103 + 138 = 241
107 + 134 = 241
109 + 132 = 241
113 + 128 = 241
127 + 114 = 241
131 + 110 = 241
137 + 104 = 241
139 + 102 = 241
149 + 92 = 241
151 + 90 = 241
157 + 84 = 241
163 + 78 = 241
167 + 74 = 241
173 + 68 = 241
179 + 62 = 241
181 + 60 = 241
191 + 50 = 241
193 + 48 = 241
197 + 44 = 241
199 + 42 = 241
211 + 30 = 241
223 + 18 = 241
227 + 14 = 241
229 + 12 = 241
233 + 8 = 241
因此,相加等于241的质数为2和239。