A092901 Number of irregular primes (A000928) less than 10^n.

0, 3, 64, 497, 3789, 30870, 261871, 2266482, 20006269

Offset: 1

Author

Eric W. Weisstein, Mar 13 2004

Keywords

• nonn
• more
• hard

Comments

Buhler maintains a list of regular and irregular primes. Data about each irregular prime includes the index of irregularity, irregular pairs, Vandiver residue and two cyclotomic residues.

Corrected using latest data from Buhler and Harvey. - T. D. Noe, Apr 27 2011

Examples

			The smallest irregular prime is 37.
		

Links

• J. Buhler, R. Crandall, R. Ernvall, T. Metsankyla and M. A. Shokrollahi, Irregular Primes and Cyclotomic Invariants to 12 Million, J. Symbolic Computation 31, 2001, 89-96.
• Joe Buhler and David Harvey, Irregular primes to 163 million, arXiv:0912.2121 [math.NT], 2009.
• Joe Buhler and David Harvey, Irregular primes to 163 million
• William Hart, David Harvey and Wilson Ong, Irregular primes to two billion, Mathematics of Computation, Vol. 86, No. 308 (2017), pp. 3031-3049; also available at arXiv:1605.02398 [math.NT], 2016.
• David Harvey, Irregular primes to two billion (includes a list of all primes less than 2^31).
• Eric Weisstein's World of Mathematics, Irregular Prime

Crossrefs

Cf. A000928.

Extensions

a(6) and a(7) from T. D. Noe, Mar 31 2004

a(8) from T. D. Noe, Apr 27 2011

a(9) from Amiram Eldar, Mar 05 2019