A028669 Galois numbers for p=7; order of group AGL(n,7).

1, 42, 98784, 11587955904, 66774437101209600, 18861003469034659931443200, 261058346935768909875766027257446400, 177055579258883302762565632026325003745732198400, 5884074751780775313126615757455645503567996488345394872320000

Offset: 0

Author

Olivier Gérard

Keywords

• nonn

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..34
• Index entries for sequences related to groups.

Crossrefs

Cf. A028365, A028665, A028667, A028673, A028675, A028679, A028681, A028685.

Cf. A132035.

Programs

Mathematica

FoldList[ #1*7^#2 (7^#2-1)&, 1, Range[ 20 ] ]
a[n_] := 7^n * Product[7^n - 7^k, {k, 0, n-1}]; Array[a, 10, 0] (* Amiram Eldar, Jul 12 2025 *)

PARI

a(n) = 7^n * prod(k = 0, n-1, 7^n - 7^k); \\ Amiram Eldar, Jul 12 2025

Formula

a(n) = 7^n * Product_{k=0..n-1} (7^n - 7^k).

a(n) ~ c * 7^(n^2+n), where c = A132035. - Amiram Eldar, Jul 12 2025