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A015009
q-factorial numbers for q=10.
11
1, 1, 11, 1221, 1356531, 15072415941, 1674711207620451, 1860790044610366931061, 20675444733360738721748118771, 2297271634742810443154153338805764581, 2552524038347870310755413660544832496799359491, 28361378203581611893021499527080870668821235178133404501
OFFSET
0,3
FORMULA
a(n) = Product_{k=1..n} (q^k - 1)/(q - 1) with q=10.
a(0) = 1, a(n) = (10^n - 1)*a(n-1)/9. - Vincenzo Librandi, Oct 26 2012
MATHEMATICA
RecurrenceTable[{a[1]==1, a[n]==((10^n-1) * a[n-1])/9}, a, {n, 15}] (* Vincenzo Librandi, Oct 26 2012 *)
Table[QFactorial[n, 10], {n, 15}] (* Bruno Berselli, Aug 14 2013 *)
PROG
(Magma) [n le 1 select 1 else (10^n-1)*Self(n-1)/9: n in [1..15]]; // Vincenzo Librandi, Oct 26 2012
CROSSREFS
KEYWORD
nonn,easy
EXTENSIONS
a(0)=1 prepended by Alois P. Heinz, Sep 08 2021
STATUS
approved