A028667 Galois numbers for p=5; order of group AGL(n,5).

1, 20, 12000, 186000000, 72540000000000, 708171750000000000000, 172882428468750000000000000000, 1055177097007236328125000000000000000000, 161006835289591673217773437500000000000000000000000, 614192019859664935862872123718261718750000000000000000000000000

Offset

0,2

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..37

Index entries for sequences related to groups.

Formula

a(n) = 5^n * Product_{k=0..n-1} (5^n - 5^k).

a(n) ~ c * 5^(n^2+n), where c = A100222. - Amiram Eldar, Jul 12 2025

Mathematica

FoldList[ #1*5^#2 (5^#2-1)&, 1, Range[ 20 ] ]
a[n_] := 5^n * Product[5^n - 5^k, {k, 0, n-1}]; Array[a, 10, 0] (* Amiram Eldar, Jul 12 2025 *)

Prog

(PARI) a(n) = 5^n * prod(k = 0, n-1, 5^n - 5^k); \\ Amiram Eldar, Jul 12 2025

Crossrefs

Cf. A028365, A028665, A028669, A028673, A028675, A028679, A028681, A028685.

Cf. A100222.

Sequence in context: A045811 A086687 A173790 * A201507 A167060 A172661

Adjacent sequences: A028664 A028665 A028666 * A028668 A028669 A028670

Keyword

nonn

Author

Olivier Gérard

Status

approved