OFFSET
0,3
COMMENTS
Partial sums of A173173.
LINKS
Andrew Howroyd, Table of n, a(n) for n = 0..1000
Mircea Merca, Inequalities and Identities Involving Sums of Integer Functions J. Integer Sequences, Vol. 14 (2011), Article 11.9.1.
Index entries for linear recurrences with constant coefficients, signature (2,0,0,-2,0,1).
FORMULA
a(n) = round(Fibonacci(n+2)/2 + (n-1)/3).
a(n) = round(Fibonacci(n+2)/2 + n/3 - 1/2).
a(n) = floor(Fibonacci(n+2)/2 + n/3 - 1/6).
a(n) = ceiling(Fibonacci(n+2)/2 + n/3 - 1/2).
a(n) = a(n-3) + Fibonacci(n)+1, n > 2.
a(n) = 2*a(n-1) - 2*a(n-4) + a(n-6), n > 5.
G.f.: x*(x^3+x^2-1) / ( (x^2+x+1)*(x^2+x-1)*(x-1)^2 ).
EXAMPLE
a(4) = 0 + 1 + 1 + 1 + 2 = 5.
MAPLE
seq(ceil(Fibonacci(n+2)/2+n/3-1/2), n=0..30)
MATHEMATICA
Accumulate[Ceiling[Fibonacci[Range[0, 50]]/2]] (* Paolo Xausa, Nov 07 2025 *)
LinearRecurrence[{2, 0, 0, -2, 0, 1}, {0, 1, 2, 3, 5, 8}, 50] (* Harvey P. Dale, Feb 05 2026 *)
PROG
(PARI) a(n)=(3*fibonacci(n+2)+2*n-1)\6 \\ Charles R Greathouse IV, Nov 02 2015
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Mircea Merca, Jan 04 2011
EXTENSIONS
a(31) onward from Andrew Howroyd, Nov 07 2025
STATUS
approved
