A028672 Pseudo Galois numbers for d=10.

1, 90, 891000, 890109000000, 89001998910000000000, 890011088900109000000000000000, 890010198889020099891000000000000000000000, 89001010988800021098899001090000000000000000000000000000, 890010100987899112108987901010099891000000000000000000000000000000000000

Offset: 0

Author

Olivier Gérard

Keywords

• nonn

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..31

Crossrefs

Cf. A028668, A028670, A028671, A028674, A028676, A028677, A028678, A028680, A028682, A028683, A028684, A028686.

Cf. A132038.

Programs

Mathematica

FoldList[ #1*10^#2 (10^#2-1)&, 1, Range[ 20 ] ]
a[n_] := 10^n * Product[10^n - 10^k, {k, 0, n-1}]; Array[a, 9, 0] (* Amiram Eldar, Jul 13 2025 *)

PARI

a(n) = 10^n * prod(k = 0, n-1, 10^n - 10^k); \\ Amiram Eldar, Jul 13 2025

Formula

a(n) = 10^n * Product_{k=0..n-1} (10^n - 10^k).

a(n) ~ c * 10^(n^2+n), where c = A132038. - Amiram Eldar, Jul 13 2025