OFFSET
1,1
COMMENTS
FORMULA
a(n) = numerator((2*n-1)/(2*n+9) + 1).
Conjecture: a(n) = 2*a(n-5) - a(n-10) = 4*A060791(n+2) with g.f. -4*x*(-3 - 4*x - x^2 - 6*x^3 - 7*x^4 - 2*x^5 - x^6 + x^8 + 2*x^9) / ( (x-1)^2*(x^4 + x^3 + x^2 + x + 1)^2 ). [R. J. Mathar, Dec 07 2010]
EXAMPLE
n=1: (2*1-1)/(2*1+9)+1 = 1/11+1 = 12/11, hence a(1) = 12;
n=2: (2*2-1)/(2*2+9)+1 = 3/13+1 = 16/13, hence a(2) = 16;
n=3: (2*3-1)/(2*3+9)+1 = 5/15+1 = 1/3+1 = 4/3, hence a(3) = 4;
MAPLE
A175784 := proc(n) local k ; k := 2*n-1 ; numer(k/(10+k)+1) ; end proc:
seq(A175784(n), n=1..30) ; # R. J. Mathar, Feb 05 2011
MATHEMATICA
Numerator[Table[k/(10 + k) + 1, {k, 1, 100, 2}]]
CROSSREFS
KEYWORD
nonn
AUTHOR
Steven J. Forsberg, Dec 04 2010
STATUS
approved