**Arithmetic progression (AP)**

AP #1 :

AP #2

rearranging the terms:

If **n = 8**

AP #1 : 7, 6, 5, 4, 3, 2, 1… 16 more words

**Arithmetic progression (AP)**

AP #1 :

AP #2

rearranging the terms:

If **n = 8**

AP #1 : 7, 6, 5, 4, 3, 2, 1… 16 more words

**Is it possible to write an infinite arithmetic progression of distinct positive integers such that if we replace each term by the sum of its digits, the new sequence is again an arithmetic progression?** 22 more words