A028671 Pseudo Galois numbers for d=9; order of group AGL(n,3^2).

1, 72, 466560, 247608990720, 10657130578027315200, 37158487365982254056334950400, 10494634615565778355427184150449750016000, 240083527795435700509596514439839216948307004751872000, 444879613680905841995130298273091805272041653799250478127267184640000

Offset: 0

Author

Olivier Gérard

Keywords

• nonn

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..32

Crossrefs

Cf. A028668, A028670, A028672, A028674, A028676, A028677, A028678, A028680, A028682, A028683, A028684, A028686.

Cf. A132037.

Programs

Mathematica

FoldList[ #1*9^#2 (9^#2-1)&, 1, Range[ 20 ] ]
a[n_] := 9^n * Product[9^n - 9^k, {k, 0, n-1}]; Array[a, 9, 0] (* Amiram Eldar, Jul 13 2025 *)

PARI

a(n) = 9^n * prod(k = 0, n-1, 9^n - 9^k); \\ Amiram Eldar, Jul 13 2025

Formula

a(n) = 9^n * Product_{k=0..n-1} (9^n - 9^k).

a(n) ~ c * 9^(n^2+n), where c = A132037. - Amiram Eldar, Jul 13 2025