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 1-4 of 4 results.

A063182 Number of cyclic subgroups of the group S_n X S_n (where S_n is the symmetric group of degree n).

Original entry on oeis.org

1, 4, 26, 314, 5222, 168632, 5736908, 291993032, 18599068328, 1547379999392, 136254185631632, 18749419634845088, 2367416741670079712, 387737484226037810048, 78779133220155242489792, 17651532033334188604514432, 3945247307615376458903485568
Offset: 1

Views

Author

Vladeta Jovovic, Jul 10 2001

Keywords

Crossrefs

Cf. A051625, A060648, (unlabeled case) A063183.

Extensions

a(9)-a(17) from Stephen A. Silver, Feb 22 2013

A062364 Number of cyclic subgroups of the group A_n X A_n (where A_n is the alternating group of degree n).

Original entry on oeis.org

1, 1, 5, 80, 1232, 35402, 1194062, 70565000, 4701427880, 368268892232, 32176642615592, 4268310912989312, 538435375681984640, 93863308664587110560, 20096819872783656177632, 4630250413602884766388352, 1005800123495980918868450432, 286583083615434477248177406080
Offset: 1

Views

Author

Vladeta Jovovic, Jul 11 2001

Keywords

Crossrefs

Cf. A063182, A063183, A051636, A020902, (unlabeled case) A062365.

Extensions

a(9)-a(18) from Stephen A. Silver, Feb 22 2013

A062365 Number of nonisomorphic cyclic subgroups of the group A_n X A_n (where A_n is the alternating group of degree n).

Original entry on oeis.org

1, 1, 2, 4, 7, 10, 17, 19, 27, 35, 54, 58, 85, 96, 106, 122, 171, 209, 272, 312, 339, 384, 504, 568, 668, 754, 867, 981, 1226, 1357, 1658, 1859, 1991, 2318, 2526, 2833, 3393, 3730, 3976, 4418, 5244, 5829, 6798, 7468, 7998, 8770, 10282, 11354, 12676, 13911
Offset: 1

Views

Author

Vladeta Jovovic, Jul 11 2001

Keywords

Examples

			Set of orders of elements of A_8 X A_8 is {1, 2, 3, 4, 5, 6, 7, 10, 12, 14, 15, 20, 21, 28, 30, 35, 42, 60, 105}, thus a(8)=19.
		

Crossrefs

Cf. A063182, A063183, A051636, A020902, (labeled case) A062364.

Extensions

More terms from David Wasserman, Jun 27 2002

A358070 Largest order of element in direct product S_n * S_n where S_n is the symmetric group.

Original entry on oeis.org

1, 1, 2, 6, 12, 30, 30, 84, 120, 210, 420, 420, 840, 1260, 2310, 4620, 5460, 5460, 13860, 13860, 27720, 32760, 60060, 60060, 120120, 180180, 180180, 360360, 360360, 510510, 1021020, 1141140, 2042040, 3063060, 3423420, 6126120, 6846840, 6846840, 8953560, 12252240
Offset: 0

Views

Author

Jack Zhang, Oct 29 2022

Keywords

Comments

Let (P,Q) be two partitions of n and lcm(P) be the LCM of all parts of P, then a(n) = max( lcm(lcm(P), lcm(Q)) ) where the maximum is taken among all pairs (P,Q). - Joerg Arndt, Dec 04 2022

Examples

			From _Joerg Arndt_, Dec 04 2022: (Start)
The 15 partitions of 7 are the following:
[ #]  [ partition ]   lcm( parts )
[ 1]  [ 1 1 1 1 1 1 1 ]   1
[ 2]  [ 1 1 1 1 1 2 ]   2
[ 3]  [ 1 1 1 1 3 ]   3
[ 4]  [ 1 1 1 2 2 ]   2
[ 5]  [ 1 1 1 4 ]   4
[ 6]  [ 1 1 2 3 ]   6
[ 7]  [ 1 1 5 ]   5
[ 8]  [ 1 2 2 2 ]   2
[ 9]  [ 1 2 4 ]   4
[10]  [ 1 3 3 ]   3
[11]  [ 1 6 ]   6
[12]  [ 2 2 3 ]   6
[13]  [ 2 5 ]  10
[14]  [ 3 4 ]  12
[15]  [ 7 ]   7
The maximum value attained is 7 * 12, so a(7) = 84.
(End)
		

Crossrefs

Cf. A000793 (largest order of element in S_n).
Cf. A063183.

Programs

  • Python3
    x=[{1},{1}]
    for i in range(2,40):
        u=[]
        for j in range(1,i):
            u.extend([k*j//math.gcd(k,j) for k in x[i-j]])
        x.append(set(u))
    xx=[set([i*j//math.gcd(i,j) for i in t for j in t]) for t in x]
    print([max(i) for i in xx][2:])
Showing 1-4 of 4 results.