- Joined
- Jun 21, 2003
Is the expression x² + x + 41 prime for all non-negative integers x?
0² + 0 + 41 = 41 (prime)
1² + 1 + 41 = 43 (prime)
2² + 2 + 41 = 47 (prime)
3² + 3 + 41 = 53 (prime)
4² + 4 + 41 = 61 (prime)
5² + 5 + 41 = 71 (prime)
etc. (?)
Note: this sequence can also be obtained by starting with 41, then add on 2, then add on 4, then 6, then 8,...
Extra credit (+3 GOE): Can you settle this question without a calculator?
MM
0² + 0 + 41 = 41 (prime)
1² + 1 + 41 = 43 (prime)
2² + 2 + 41 = 47 (prime)
3² + 3 + 41 = 53 (prime)
4² + 4 + 41 = 61 (prime)
5² + 5 + 41 = 71 (prime)
etc. (?)
Note: this sequence can also be obtained by starting with 41, then add on 2, then add on 4, then 6, then 8,...
Extra credit (+3 GOE): Can you settle this question without a calculator?
MM