OFFSET
0,3
COMMENTS
Each term is F(k) or F(k)^2 or F(k-1)*F(k+1) for appropriate k, F=A000045, the Fibonacci numbers.
LINKS
Reinhard Zumkeller, Table of n, a(n) for n = 0..1000
FORMULA
G.f.: -x*(x^16+2*x^15+4*x^14 +5*x^13+3*x^12+x^11 -4*x^10-7*x^9-10*x^8 -12*x^7-14*x^6-14*x^5 -12*x^4-10*x^3-6*x^2-3*x-1) / ((x+1)*(x^2+1)*(x^4+1)*(x^4+x^2-1)*(x^4-x^2-1)). - Alois P. Heinz, May 05 2011
EXAMPLE
a(10) = F(8) = 21;
a(11) = F(4) * F(6) = 3 * 8 = 24;
a(12) = F(5)^2 = 5^2 = 25;
a(13) = F(9) = 34;
a(14) = F(10) = 55;
a(15) = F(6)^2 = 8^2 = 64;
a(16) = F(5) * F(7) = 5 * 13 = 65;
a(17) = F(11) = 89;
a(18) = F(12) = 144;
a(19) = F(6) * F(8) = 8 * 21 = 168;
a(20) = F(7)^2 = 13^2 = 169.
MAPLE
a:= n-> `if`(n<6, n, (Matrix(15, (i, j)-> `if`(j=i+1, 1, `if`(i=15, [-1$4, 2$8, -1$3][j], 0)))^n. <<0, 1, 1, 0, 0, [1$4][], 2, 2, 3, 3, 4, 5>>)[10, 1]): seq(a(n), n=0..50); # Alois P. Heinz, May 04 2011
MATHEMATICA
CoefficientList[Series[-x*(x^16+2*x^15+4*x^14 +5*x^13+3*x^12+x^11 -4*x^10 -7*x^9-10*x^8 -12*x^7-14*x^6-14*x^5 -12*x^4-10*x^3-6*x^2-3*x-1)/((x+1)*(x^2+1)*(x^4+1)*(x^4+x^2-1)*(x^4-x^2-1)), {x, 0, 50}], x] (* G. C. Greubel, Jan 11 2018 *)
PROG
(Haskell)
a190018 n = a190018_list !! n
a190018_list = 0 : drop 2 (merge (merge fibs $
map (^ 2) fibs) $ zipWith (*) fibs (drop 2 fibs))
where fibs = 0 : 1 : zipWith (+) fibs (tail fibs)
merge xs'@(x:xs) ys'@(y:ys)
| x < y = x : merge xs ys'
| x == y = x : merge xs ys
| otherwise = y : merge xs' ys
(PARI) x='x+O('x^50); concat([0], Vec(-x*(x^16+2*x^15+4*x^14 +5*x^13 +3*x^12+x^11 -4*x^10-7*x^9-10*x^8 -12*x^7-14*x^6-14*x^5 -12*x^4-10*x^3 -6*x^2-3*x-1)/((x+1)*(x^2+1)*(x^4+1)*(x^4+x^2-1)*(x^4-x^2-1)))) \\ G. C. Greubel, Jan 11 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, May 04 2011
STATUS
approved