OFFSET
1,2
COMMENTS
Partial sums of A015565. - Mircea Merca, Dec 28 2010
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
Index entries for linear recurrences with constant coefficients, signature (8,1,-8).
FORMULA
a(n) = 8*a(n-1) + a(n-2) - 8*a(n-3).
a(n) = 2^(3*n+3)/63 - 1/14 - (-1)^n/18. - R. J. Mathar, Jan 08 2011
From Paul Barry, Apr 04 2008: (Start)
G.f. x/((1-x^2)*(1-8*x));
a(n) = (1/3)*Sum_{k=0..n} A001045(3k). (End)
a(n) = floor(8^(n+1)/9)/7 = floor((8*8^n-1)/63) = round((8*8^n-8)/63) = round((16*8^n-9)/63) = ceiling((8*8^n-8)/63). a(n) = a(n-2) + 8^(n-1), n > 2. - Mircea Merca, Dec 28 2010
MAPLE
seq(1/7*floor(8^(n+1)/9), n=1..22); # Mircea Merca, Dec 27 2010
MATHEMATICA
Table[FromDigits[PadRight[{}, n, {1, 0}], 8], {n, 20}] (* or *) LinearRecurrence[ {8, 1, -8}, {1, 8, 65}, 20] (* Harvey P. Dale, Jan 20 2021 *)
PROG
(Magma) [Round((8*8^n-8)/63): n in [1..30]]; // Vincenzo Librandi, Jun 25 2011
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
STATUS
approved