William

Asif, Yes, I looked at the information on non-trivial perfect digital invariants. Near the end of that reference, there is a short section entitled "Relation to happy numbers" that indicates that in order for a number to be happy, it needs to be a perfect digital invariant with the value of 1. In this case, the invariant is 8 (or 22 in base-3), so I interprete that as saying that it is a non-trivial PDI, but not happy.

on 10 Jan 2020 at 18:10

William submitted Solution 2088296 to Problem 45252. Restricted Addition v1

on 10 Jan 2020 at 17:38

William submitted Solution 2088294 to Problem 45252. Restricted Addition v1

on 10 Jan 2020 at 17:36

William liked Problem 45264. Restricted Addition v3

on 10 Jan 2020 at 17:28

William submitted Solution 2088276 to Problem 45264. Restricted Addition v3

on 10 Jan 2020 at 17:25

William submitted Solution 2088273 to Problem 45264. Restricted Addition v3

on 10 Jan 2020 at 17:21

William submitted Solution 2088272 to Problem 45264. Restricted Addition v3

on 10 Jan 2020 at 17:20

William submitted Solution 2088051 to Problem 45261. Query every vertices neighbor indices

on 10 Jan 2020 at 13:57

William submitted Solution 2084844 to Problem 45260. Alternate list of elements

on 9 Jan 2020 at 13:37

William submitted Solution 2084843 to Problem 45260. Alternate list of elements

on 9 Jan 2020 at 13:35

William submitted Solution 2084847 to Problem 45260. Alternate list of elements

on 9 Jan 2020 at 13:33

William submitted Solution 2084032 to Problem 45259. Query edges list

on 8 Jan 2020 at 20:03

William submitted Solution 2084028 to Problem 45259. Query edges list

on 8 Jan 2020 at 19:59

William submitted Solution 2083150 to Problem 45258. Restricted Addition v2

on 7 Jan 2020 at 23:59

William submitted Solution 2083135 to Problem 45257. Find neighbor triangle indices

on 7 Jan 2020 at 23:22

William submitted Solution 2083134 to Problem 45257. Find neighbor triangle indices

on 7 Jan 2020 at 23:20

William submitted Solution 2083118 to Problem 45256. Query a vertex neighbors

on 7 Jan 2020 at 22:46

William submitted Solution 2082056 to Problem 926. Unique: Speed Enhancement for uint(8,16,32)

on 6 Jan 2020 at 21:45

William submitted Solution 2082055 to Problem 926. Unique: Speed Enhancement for uint(8,16,32)

on 6 Jan 2020 at 21:40

William submitted Solution 2082053 to Problem 926. Unique: Speed Enhancement for uint(8,16,32)

on 6 Jan 2020 at 21:34

William liked Problem 45250. Be happy

on 6 Jan 2020 at 20:46

William submitted a Comment to Problem 45250. Be happy

Well, it appears to me that the number 742356 is a pre-periodic point of the perfect digital invariant n=8 in base 3. However, since the perfect digital invariant is n=8 rather than n=1, this is not a happy number. At least, that is how I read it!

on 6 Jan 2020 at 19:30

William submitted a Comment to Problem 45250. Be happy

Asif: Yes, I am now seeing a discrepancy with problem 6, but all the others agree with my code.

on 6 Jan 2020 at 4:06

William liked Problem 45252. Restricted Addition v1

on 5 Jan 2020 at 15:52

William submitted Solution 2080743 to Problem 45252. Restricted Addition v1

on 5 Jan 2020 at 15:49

William submitted a Comment to Problem 45250. Be happy

Asif: If I am reading that reference correctly, then test suite problems 4 and 7 are incorrect. In fact, problem 4 has base b=4, and according to the reference b=4 is a "happy base" in which *all* numbers are happy.

on 5 Jan 2020 at 15:16

William submitted Solution 2080377 to Problem 45251. Last non-zero digit

on 5 Jan 2020 at 0:05

William submitted a Comment to Problem 45255. Find the sequence

Asif, Test suite problems 6-10 are pretty peculiar! Did you mean to have them that way?

on 4 Jan 2020 at 22:31

William submitted Solution 2080361 to Problem 45255. Find the sequence

on 4 Jan 2020 at 22:28

William submitted Solution 2080348 to Problem 45254. Tribonacci Sequence

on 4 Jan 2020 at 22:04

William submitted Solution 2080342 to Problem 45253. Pell numbers

on 4 Jan 2020 at 21:57