[seqfan] Subsets with prime sums again - Part 2

[Christopher Gribble]

Here is another triangle whose column sums give Zak's sequence

4, 26, 444, 11998, 382716, 15844060, .

 

This is related to the method of subset construction.

For N = 2, the subsets are {1, 2}, {1, 4}, {2, 3}, {3, 4}.

The first member is 1 in 2 subsets, 2 in 1 subset and 3 in 1 subset.

 

            Frequency with which first

            subset member values occur

First   N   2      3      4

Member

 1          2      8    111

 2          1      8     88

 3          1      4     67

 4                 4     55

 5                 1     42

 6                 1     32

 7                       23

 8                       15

 9                        6

10                        3

11                        2

 

Total       4     26    444

 

This triangle is not in the OEIS either.

 

Best regards,

 

Chris Gribble