|
|
A308961
|
|
Numbers k not divisible by 10 such that k^2 and 2*k are in A046030.
|
|
0
|
|
|
2, 7, 97, 997, 9997, 20247, 99997, 999997, 9999997, 99999997, 999999997, 2224745247, 9999999997, 99999999997, 999999999997, 9999999999997, 99999999999997, 999999999999997, 9999999999999997, 99999999999999997
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
10^j - 3 are terms. Most of the terms so far are of the form 10^j - 3. Are there other terms not of this form besides 2, 20247, and 2224745247?
If k is a term, then primes of the form k*10^j + 1 for j >= A055642(2*k) are in A308917 and primes of the form 10^j + k for j >= A055642(k^2) are in A308917.
|
|
LINKS
|
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,base
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|