OFFSET
0,2
COMMENTS
The sequence of last digits, a(n) mod 10, is periodic with period length 5: repeat 0, 4, 8, 2, 6.
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..200
Index entries for linear recurrences with constant coefficients, signature (17,-16)
FORMULA
a(n) = (A141060(n)-3)/10.
a(n) = 16*a(n-1)+4.
a(n) = 4*A131865(n-1).
a(n+1)-a(n) = A013709(n).
G.f.: 4*x / ( (16*x-1)*(x-1) ). - R. J. Mathar, Jul 02 2011
MAPLE
MATHEMATICA
s=0; lst={s}; Do[s+=2^n; AppendTo[lst, s], {n, 2, 5!, 4}]; lst (* Vladimir Joseph Stephan Orlovsky, Nov 07 2008 *)
PROG
(Magma) [(4/15)*(16^n-1): n in [0..25]]; // Vincenzo Librandi, May 25 2011
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Paul Curtz, Jul 30 2008
EXTENSIONS
More terms from Vladimir Joseph Stephan Orlovsky, Nov 07 2008
STATUS
approved