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.

Showing 1-6 of 6 results.

A062766 Number of nonisomorphic cyclic subgroups of general affine group AGL(n,2).

Original entry on oeis.org

2, 4, 6, 11, 16, 23, 32, 46, 62, 83, 114, 158, 212, 276, 351, 442, 562, 726, 933, 1191, 1498, 1876
Offset: 1

Views

Author

Vladeta Jovovic, Jul 17 2001

Keywords

Examples

			a(5)=16 because the set of orders of elements of AGL(5,2) is {1,2,3,4,5,6,7,8,10,12,14,15,21,28,30,31}.
		

Crossrefs

Cf. A062710 (labeled case), A053651.

Extensions

a(13)-a(22) from Sean A. Irvine, Jan 11 2022

A053658 Number of nonisomorphic cyclic subgroups of general linear group GL(n,3).

Original entry on oeis.org

2, 6, 8, 18, 26, 42, 62, 94, 130, 188, 264, 372, 506, 678
Offset: 1

Views

Author

Vladeta Jovovic, Mar 22 2000

Keywords

References

  • V. Jovovic, The cycle index polynomials of some classical groups, Belgrade, 1995, unpublished.

Crossrefs

Extensions

a(11)-a(15) from Sean A. Irvine, Jan 10 2022

A053660 Number of nonisomorphic cyclic subgroups of general linear group GL(n,4).

Original entry on oeis.org

2, 6, 12, 18, 36, 56, 92, 138, 220, 338, 520
Offset: 1

Views

Author

Vladeta Jovovic, Mar 22 2000

Keywords

References

  • V. Jovovic, The cycle index polynomials of some classical groups, Belgrade, 1995, unpublished.

Crossrefs

Extensions

a(8)-a(11) from Sean A. Irvine, Jan 10 2022

A062250 Number of cyclic subgroups of Chevalley group A_n(2) (the group of nonsingular n X n matrices over GF(2) ).

Original entry on oeis.org

1, 5, 79, 6974, 2037136, 2890467344, 14011554132032, 325330342132674560, 27173394819858612320256, 10158190320726534408118452224, 13156630408268153048253765001412608, 80280189722884518774834501142737770774528
Offset: 1

Views

Author

Ahmed Fares (ahmedfares(AT)my-deja.com), Jul 01 2001

Keywords

Examples

			a(3) = 1/phi(1)+21/phi(2)+56/phi(3)+42/phi(4)+48/phi(7) = 79.
		

References

  • V. Jovovic, The cycle index polynomials of some classical groups, Belgrade, 1995, unpublished.

Crossrefs

Formula

a(n) = Sum_{d} |{g element of A_n(2): order(g)=d}|/phi(d), where phi=Euler totient function, cf. A000010.

Extensions

More terms from Vladeta Jovovic, Jul 04 2001

A316560 Number of cyclic subgroups of the group GL(2, Z(n)), counting conjugates as distinct.

Original entry on oeis.org

1, 5, 28, 62, 176, 148, 610, 696, 1252, 920, 2296, 1972, 4874, 3523, 6040, 6320, 8136, 7348, 14984, 13568, 22124, 11920, 17396, 23952, 29846, 28172, 38044, 47656, 47282, 32908, 75036, 53520, 71768, 42312, 145852, 99892, 123524, 88456, 187036, 179200, 152290
Offset: 1

Views

Author

Andrew Howroyd, Jul 06 2018

Keywords

Crossrefs

Programs

  • GAP
    Concatenation([1], List([2..7], n->Sum( Filtered( ConjugacyClassesSubgroups( GL(2, Integers mod n)), x->IsCyclic( Representative(x))), Size)));
    
  • PARI
    MatOrder(M)={my(id=matid(#M), k=1, N=M); while(N<>id, k++;N=N*M); k}
    a(n)={sum(a=0, n-1, sum(b=0, n-1, sum(c=0, n-1, sum(d=0, n-1, my(M=Mod([a, b; c, d], n)); if(gcd(lift(matdet(M)), n)==1, 1/eulerphi(MatOrder(M)))))))}

Formula

a(n) = Sum_{k=1..A316565(n)} 1/phi(A316566(n,k)).

A211171 Exponent of general linear group GL(n,2).

Original entry on oeis.org

1, 6, 84, 420, 26040, 78120, 9921240, 168661080, 24624517680, 270869694480, 554470264600560, 7208113439807280, 59041657185461430480, 2538791258974841510640, 383357480105201068106640, 98522872387036674503406480, 25826982813282567927671981480160
Offset: 1

Views

Author

Alexander Gruber, Jan 31 2013

Keywords

Comments

a(n) is the smallest integer for which x^a(n) = 1 for any x in GL(n,2).

Examples

			n = 2: GL(2,2) is isomorphic to S3 which has exponent 6 (see: A003418).
n = 3: The set of element orders of GL(3,2) is {1,2,3,4,7} so the exponent is 84.
n = 5: The set of element orders of GL(5,2) is {1,2,3,4,5, 6,7,8,12,14, 15,21,31} so the exponent is 26040 (see: A053651).
		

Crossrefs

Cf. A006951 (number of conjugacy classes in GL(n,2)).

Programs

  • Magma
    for n in [1..18] do
    Exponent(GL(n,2));
    end for;
    
  • Maple
    with(numtheory):
    a:= proc(n) local t; t:= 2^ilog2(n);
          `if`(tAlois P. Heinz, Feb 04 2013
  • Mathematica
    f[q_, n_] := With[{p = Sort[Divisors[q]][[2]]},
      p^Ceiling[Log[p, n]] Product[Cyclotomic[k, q], {k, n}]]; f[2,#]&/@Range[100]
  • PARI
    a(n) = 2^ceil(log(n)/log(2))*prod(k=1, n, polcyclo(k, 2)); \\ Michel Marcus, Jan 29 2020

Formula

a(n) = 2^ceiling(log_2(n)) * Product_{k=1..n} (k-th cyclotomic polynomial evaluated at 2).
a(n) = A034268(n)*A062383(n+1). - Michel Marcus, Jul 29 2022
Showing 1-6 of 6 results.