A106745 Numbers n such that 101101 * 10^n + 1 is prime.

5, 6, 7, 12, 21, 25, 300, 305, 600, 689, 742, 1418, 1547, 1744, 5275, 6355, 7477, 15312, 16772, 33047

Offset

1,1

Comments

These are anti-Yarborough primes, i.e. primes containing just 1's and 0's and they have all been certified. Primality proof for the largest: PFGW Version 20041001.Win_Stable (v1.2 RC1b) [FFT v23.8] Primality testing 101101*10^33047+1 [N-1, Brillhart-Lehmer-Selfridge] Running N-1 test using base 3 Calling Brillhart-Lehmer-Selfridge with factored part 69.89% 101101*10^33047+1 is prime! (194.9694s+0.0907s)

Links

Table of n, a(n) for n=1..20.

R. Ondrejka, The Top Ten: a Catalogue of Primal Configurations.

Prog

(PARI) is(n)=ispseudoprime(101101*10^n+1) \\ Charles R Greathouse IV, Jun 06 2017

Crossrefs

Cf. A020449.

Sequence in context: A327301 A247522 A011761 * A165776 A327106 A003273

Adjacent sequences: A106742 A106743 A106744 * A106746 A106747 A106748

Keyword

nonn,more

Author

Jason Earls, May 16 2005

Status

approved