OFFSET
0,5
COMMENTS
A242105 gives the first nonzero terms per row, without repetitions. - Reinhard Zumkeller, Sep 06 2015
LINKS
Reinhard Zumkeller, Rows n = 0..125 of triangle, flattened
L. Haddad and C. Helou, Finite Sequences Dominated by the Squares, Journal of Integer Sequences, Volume 18, 2015, Issue 1, Article 15.1.8.
EXAMPLE
Triangle begins:
1,
1,1,
0,2,1,
0,2,3,1,
0,2,5,4,1,
0,0,7,9,5,1,
0,0,7,16,14,6,1,
0,0,7,23,30,20,7,1,
0,0,7,30,53,50,27,8,1,
0,0,7,37,83,103,77,35,9,1,
0,0,0,44,120,186,180,112,44,10,1,
0,0,0,44,164,306,366,292,156,54,11,1,
...
PROG
(Haskell)
a261897 n k = a261897_tabl !! n !! (k-1)
a261897_row n = a261897_tabl !! n
a261897_tabl = [1] : f 1 0 [1] where
f t h xs | t <= (h + 1) ^ 2 = ys : f (t + 1) h ys
| otherwise = ys' : f (t + 1) (h + 1) ys'
where ys = zipWith (+) ([0] ++ xs) (xs ++ [0])
ys' = zipWith (+) ([0] ++ xs) (us ++ (0:vs) ++ [0])
(us, _:vs) = splitAt h xs
-- Reinhard Zumkeller, Sep 06 2015
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
N. J. A. Sloane, Sep 05 2015
STATUS
approved