cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A334994 Orders of the groups PSL(m,q) in increasing order as q runs through the prime powers (without repetitions).

Original entry on oeis.org

6, 12, 60, 168, 360, 504, 660, 1092, 2448, 3420, 4080, 5616, 6072, 7800, 9828, 12180, 14880, 20160, 25308, 32736, 34440, 39732, 51888, 58800, 74412, 102660, 113460, 150348, 178920, 194472, 246480, 262080, 265680, 285852, 352440, 372000, 456288, 515100, 546312
Offset: 1

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Author

Michel Marcus, May 19 2020

Keywords

Comments

60 is the order of PSL(2,4) or PSL(2,5).
168 is the order of PSL(2,7) or PSL(3,2).
20160 is the order of PSL(4,2) or PSL(3,4).
See A334884 and A335000 for variations of this sequence.

Examples

			#PSL(2,7) = (7^2-1)*7/gcd(2,6) = 168 = a(4), and,
#PSL(3,2) = (2^3-1)*(2^3-2)*2^2/gcd(3,1) = 168 = a(4).
		

Crossrefs

Cf. A117762 (PSL(2, prime(n))).
Cf. A334884 and A335000 (both with repetitions, but different).

Formula

#PSL(m,q) = (Product_{j=0..m-2} (q^m - q^j)) * q^(m-1) / gcd(m,q-1). - Bernard Schott, May 19 2020