OFFSET
0,3
LINKS
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
AUTHOR
EXTENSIONS
a(0)=1 prepended by Alois P. Heinz, Sep 08 2021
STATUS
approved