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.
%I A015008 #30 Jul 06 2025 10:11:23
%S A015008 1,1,10,910,746200,5507702200,365876657146000,218747042884536166000,
%T A015008 1177042838234827583459440000,57001313848230245122464621625840000,
%U A015008 24843911488189148287648216529610193612000000,97453533413342456299179976631323547842824103012000000
%N A015008 q-factorial numbers for q=9.
%H A015008 Vincenzo Librandi, <a href="/A015008/b015008.txt">Table of n, a(n) for n = 0..40</a>
%H A015008 <a href="/index/Fa#factorial">Index entries for sequences related to factorial numbers</a>.
%F A015008 a(n) = Product_{k=1..n} (9^k - 1) / (9 - 1).
%F A015008 a(0) = 1, a(n) = (9^n - 1)*a(n-1)/8. - _Vincenzo Librandi_, Oct 26 2012
%F A015008 From _Amiram Eldar_, Jul 05 2025: (Start)
%F A015008 a(n) = Product_{k=1..n} A002452(k).
%F A015008 a(n) ~ c * 3^(n*(n+1))/8^n, where c = A132037. (End)
%t A015008 RecurrenceTable[{a[1]==1, a[n]==((9^n - 1) * a[n-1])/8}, a, {n, 15}] (* _Vincenzo Librandi_, Oct 26 2012 *)
%t A015008 Table[QFactorial[n, 9], {n, 15}] (* _Bruno Berselli_, Aug 14 2013 *)
%o A015008 (Magma) [n le 1 select 1 else (9^n - 1)*Self(n-1)/8: n in [1..15]]; // _Vincenzo Librandi_, Oct 26 2012
%Y A015008 Cf. A015001, A015002, A015004, A015005, A015006, A015007, A015009, A015011.
%Y A015008 Column q=9 of A069777.
%Y A015008 Cf. A002452, A132037.
%K A015008 nonn,easy
%O A015008 0,3
%A A015008 _Olivier Gérard_
%E A015008 a(0)=1 prepended by _Alois P. Heinz_, Sep 08 2021