OFFSET
0,5
COMMENTS
Sum of n-th row = 2*A001629(n+1). - Reinhard Zumkeller, Oct 07 2012
LINKS
Reinhard Zumkeller, Rows n = 0..120 of triangle, flattened
L. Carlitz, A Fibonacci array, Fib. Quart. 1(#2) (1963), 217-28.
FORMULA
a(0, n)=Fib(n), a(1, n)=Fib(n+2), a(r, n)=a(r-1, n)+a(r-2, n), r >= 2.
G.f.: (x+y)/((1-x-x^2)*(1-y-y^2)). [U coordinates]
EXAMPLE
0;
1 1;
1 2 1;
2 3 3 2;
3 5 4 5 3;
...
PROG
(Haskell)
a039913 n k = a039913_tabl !! n !! k
a039913_row n = a039913_tabl !! n
a039913_tabl = [[0], [1, 1]] ++ f [0] [1, 1] where
f us@(u:us') vs@(v:vs') = ws : f vs ws where
ws = [u + v, u + v + v] ++ zipWith (+) us vs'
-- Reinhard Zumkeller, Oct 07 2012
CROSSREFS
KEYWORD
AUTHOR
EXTENSIONS
More terms from Larry Reeves (larryr(AT)acm.org), Sep 28 2000
STATUS
approved