A354676 a(n) = number of near-Wieferich primes with |A| <= 100 less than 10^n.

3, 24, 105, 154, 213, 243, 268, 288, 307

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 | 105 | 168 | 62.500000

4 | 154 | 1229 | 12.530512

5 | 213 | 9592 | 2.220600

6 | 243 | 78498 | 0.309562

7 | 268 | 664579 | 0.040326

8 | 288 | 5761455 | 0.004998

9 | 307 | 50847534 | 0.000603

Crossrefs

Cf. A006880, A195988, A246568, A258367, A353141, A354675, A354677, A354678.

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) <= 100, i++))