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A173766
(10^n+11)/3.
5
7, 37, 337, 3337, 33337, 333337, 3333337, 33333337, 333333337, 3333333337, 33333333337, 333333333337, 3333333333337, 33333333333337, 333333333333337, 3333333333333337, 33333333333333337, 333333333333333337
OFFSET
1,1
FORMULA
a(n)=10*a(n-1)-33 (with a(1)=7)
Contribution from Bruno Berselli, Jun 09 2010: (Start)
G.f.: x*(7-40*x)/((1-x)*(1-10*x)).
a(n)-11*a(n-1)+10*a(n-2) = 0 for n>2. (End)
EXAMPLE
For n=2, a(2)=10*7-33=37; n=3, a(3)=10*37-33=337; n=4, a(4)=10*337-33=3337
MATHEMATICA
NestList[10#-33&, 7, 20] (* Harvey P. Dale, Aug 01 2022 *)
CROSSREFS
Cf. A093168.
Cf. A086574, A163449. [From Bruno Berselli, Jun 09 2010]
Sequence in context: A075996 A356127 A343568 * A093168 A330388 A371710
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Feb 24 2010
EXTENSIONS
I reduced the fraction in the definition to "(10^n+11)/3". The factor 3 was simply irrelevant. - Ivan Panchenko, Jun 05 2010
STATUS
approved