OFFSET
0,1
COMMENTS
Digital root of any number in this sequence = 8. Any partial sum of digits of any number in this sequence also belongs to this sequence. - Artur Jasinski, Dec 16 2007
LINKS
Tanya Khovanova, Recursive Sequences
INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 970
Index entries for linear recurrences with constant coefficients, signature (2,-1).
FORMULA
a(n) = 18*n-a(n-1)+7. - Vincenzo Librandi, Nov 19 2010
a(0)=8, a(1)=17, a(n) = 2*a(n-1)-a(n-2). G.f.: (8+x)/(1-x)^2. - Colin Barker, Jan 24 2012
MAPLE
MATHEMATICA
Array[9*#+8&, 100, 0] (* Vladimir Joseph Stephan Orlovsky, Dec 14 2009 *)
PROG
(Haskell)
a017257 = (+ 8) . (* 9)
a017257_list = 8 : map (+ 9) a017257_list -- Reinhard Zumkeller, Jul 21 2013
(PARI) a(n)=9*n+8 \\ Charles R Greathouse IV, Sep 28 2015
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved