On 01/14/2014 12:42 PM, Eric Angelini wrote: > 13, 19, 23, 29, 39, 46, 49, 59, 69, 79, 89, 103, 109, 127, 203, 209, 234 Unless I got it wrong you forgot a few numbers, like 26. The result is your sequence A210582, a subset of modest numbers. Giovanni