A354678 a(n) = number of near-Wieferich primes with |A| <= 10000 less than 10^n.

3, 24, 167, 1228, 5250, 8851, 11922, 14549, 16863

Offset: 1

Author

Felix Fröhlich, Jun 02 2022

Keywords

• nonn
• hard
• more

Comments

n | a(n) | A006880(n) | a(n)/A006880(n)*100

---------------------------------------------

1 | 3 | 4 | 75.000000

2 | 24 | 25 | 96.000000

3 | 167 | 168 | 99.404761

4 | 1228 | 1229 | 99.918633

5 | 5250 | 9592 | 54.733110

6 | 8851 | 78498 | 11.275446

7 | 11922 | 664579 | 1.793917

8 | 14549 | 5761455 | 0.252523

9 | 16863 | 50847534 | 0.033163

Crossrefs

Cf. A006880, A195988, A246568, A258367, A353141, A354675, A354676, A354677.

Programs

PARI

a258367(n) = abs(centerlift(Mod(2, n^2)^((n-1)/2))\/n) \\ after Charles R Greathouse IV in A258367
my(i=0, x=10); forprime(p=3, , if(p > x, print1(i, ", "); x=10*x); if(a258367(p) <= 10000, i++))