A385144 - cp's OEIS frontend

A385144 a(n) is the smallest 2n + 1 digit prime consisting of a string of 2n - 1 identical digits d sandwiched between two same digits different from d, or -1 if no such prime exists.

n	a(n)
1	101
2	13331
3	1333331
4	188888881
5	74444444447
6	1666666666661
7	188888888888881
8	16666666666666661
9	1666666666666666661
10	155555555555555555551
11	75555555555555555555557
12	-1
13	-1
14	72222222222222222222222222227
15	3111111111111111111111111111113
16	155555555555555555555555555555551

[101, 13331, 1333331, 188888881, 74444444447, 1666666666661, 188888888888881, 16666666666666661, 1666666666666666661, 155555555555555555551, 75555555555555555555557, -1, -1, 72222222222222222222222222227, 3111111111111111111111111111113, 155555555555555555555555555555551]

cp's OEIS Frontend

A385144 a(n) is the smallest 2n + 1 digit prime consisting of a string of 2n - 1 identical digits d sandwiched between two same digits different from d, or -1 if no such prime exists.

Table of values

List of values

cp's OEIS Frontend

A385144 a(n) is the smallest 2*n + 1 digit prime consisting of a string of 2*n - 1 identical digits d sandwiched between two same digits different from d, or -1 if no such prime exists.

Table of values

List of values

A385144 a(n) is the smallest 2n + 1 digit prime consisting of a string of 2n - 1 identical digits d sandwiched between two same digits different from d, or -1 if no such prime exists.