Find the next number: 124, 370, 205, 301, 517, 424, 826, 427, 871, ____

Averages of certain digits go a long way in this problem.

this is a list of prime numbers multiplied by the sum of their digits, starting with 31:

31 x (3+1) = 124
37 x (3+7) = 370
41 x (4+1) = 205
43 x (4+3) = 301
47 x (4+7) = 517
53 x (5+3) = 424
59 x (5+9) = 826
61 x (6+1) = 427
67 x (6+7) = 871

so the next number is:

71 x (7+1) = 568

Posted by Gus on 2004-06-22 18:38:30