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A108975 Product of all primes with primitive root 2 less than or equal to some prime with primitive root 2. 1
3, 15, 165, 2145, 40755, 1181895, 43730115, 2317696095, 136744069605, 8341388245905, 558873012475635, 46386460035477705, 4685032463583248205, 501298473603407557935, 65670100042046390089485 (list; graph; refs; listen; history; text; internal format)



The poster by Arnold and Monagan reports that the cyclotomic polynomial of order a(6) is the first cyclotomic polynomial whose height is greater than its order. They also report the height of the cyclotomic polynomial Phi(a(7),x) is greater than the order squared. It is also true that k=a(5) is the least order such that the height of Phi(k,x) is greater than the square root of the order. - T. D. Noe, Apr 22 2008

Partial products of A001122. - Charles R Greathouse IV, Jun 21 2013


Table of n, a(n) for n=1..15.

Andrew Arnold and Michael Monagan, The Height of the 3,234,846,615th Cyclotomic Polynomial is Big (2,888,582,082,500,892,851)


3 is the first prime with primitive root 2, so the first term is 3. 5 is the next prime with primitive root 2, so the next term is 3*5=15. 11 is the next prime with primitive root 2, so the next term is 3*5*11=165.


Cf. A001122.

Sequence in context: A304998 A105611 A329557 * A097489 A080696 A015013

Adjacent sequences:  A108972 A108973 A108974 * A108976 A108977 A108978




Douglas Stones (dssto1(AT)student.monash.edu.au), Jul 27 2005



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Last modified June 18 04:41 EDT 2021. Contains 345098 sequences. (Running on oeis4.)