OFFSET
0,4
COMMENTS
FORMULA
Exponential Riordan array [1/(cos(sqrt(3)*x)-sin(sqrt(3)*x)/sqrt(3)), sin(sqrt(3)*x)/(sqrt(3)*cos(sqrt(3)*x)-sin(sqrt(3)*x))].
EXAMPLE
Triangle begins
1,
1, 1,
5, 4, 1,
21, 33, 9, 1,
153, 264, 114, 16, 1,
1209, 2769, 1410, 290, 25, 1,
12285, 32076, 20259, 5040, 615, 36, 1,
140589, 432657, 314811, 94899, 14175, 1155, 49, 1,
1871217, 6475536, 5423076, 1886304, 337974, 33936, 1988, 64, 1
Production matrix begins
1, 1,
4, 3, 1,
0, 16, 5, 1,
0, 0, 36, 7, 1,
0, 0, 0, 64, 9, 1,
0, 0, 0, 0, 100, 11, 1,
0, 0, 0, 0, 0, 144, 13, 1,
0, 0, 0, 0, 0, 0, 196, 15, 1,
0, 0, 0, 0, 0, 0, 0, 256, 17, 1
0, 0, 0, 0, 0, 0, 0, 0, 324, 19, 1
MATHEMATICA
* The function RiordanArray is defined in A256893. *)
RiordanArray[1/(Cos[Sqrt[3]*#] - Sin[Sqrt[3]*#]/Sqrt[3])&, Sin[Sqrt[3]*#]/ (Sqrt[3]*Cos[Sqrt[3]*#] - Sin[Sqrt[3]*#])&, 11, True] // Flatten (* Jean-François Alcover, Jul 19 2019 *)
CROSSREFS
KEYWORD
AUTHOR
Paul Barry, Dec 05 2010
STATUS
approved