examples of regular primes
Examples:
- 1.
These are all the irregular primes
up to :
37, 59, 67, 101, 103, 131, 149, 157, 233, 257, 263, 271,
283, 293, 307, 311, 347, 353, 379, 389, 401,
409, 421, 433, 461, 463, 467, 491, 523, 541,
547, 557, 577, 587, 593, 607, 613, 617, 619,
631, 647, 653, 659, 673, 677, 683, 691, 727,
751, 757, 761, 773, 797, 809, 811, 821, 827,
839, 877, 881, 887, 929, 953, 971, 1061.(for this, see the http://www.research.att.com/ njas/sequences/Seis.htmlOn-Line Encyclopedia of Integer Sequences, http://www.research.att.com/cgi-bin/access.cgi/as/njas/sequences/eisA.cgi?Anum=A000928sequence A000928)
- 2.
The following are the first few class numbers
of the cyclotomic fields
, where is a primitive -th root of unity
:
An excellent reference for this is [1].
Remarks:
- –
Notice that divides , and divides , thus are irregular primes (see above).
- –
The class number of the cyclotomic fields grows very quickly with . For example, is the last cyclotomic field of class number 1.
- –
References
- 1 L. C. Washington, Introduction to Cyclotomic Fields,Springer-Verlag, New York.