This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A110165 Riordan array (1/sqrt(1-6x+5x^2),(1-3x-sqrt(1-6x+5x^2))/(2x). 4
 1, 3, 1, 11, 6, 1, 45, 30, 9, 1, 195, 144, 58, 12, 1, 873, 685, 330, 95, 15, 1, 3989, 3258, 1770, 630, 141, 18, 1, 18483, 15533, 9198, 3801, 1071, 196, 21, 1, 86515, 74280, 46928, 21672, 7210, 1680, 260, 24, 1, 408105, 356283, 236736, 119154, 44982, 12510, 2484, 333, 27, 1 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Columns include A026375,A026376,A026377. Inverse is A110168. Rows sums are A110166. Diagonal sums are A110167. LINKS FORMULA Number triangle T(n, k)=sum{j=0..n, C(n, j)C(2j, j+k)} T(n,0) = 3*T(n-1,0) + 2*T(n-1,1), T(n,k) = T(n-1,k-1) + 3*T(n-1,k) + T(n-1,k+1) for k>0, T(0,0) = 1, T(n,k) = 0 if k<0 or if k>n. - Philippe Deléham, Jan 24 2014 EXAMPLE Rows begin 1; 3,1; 11,6,1; 45,30,9,1; 195,144,58,12,1; 873,685,330,95,15,1; Production array begins: 3...1 2...3...1 0...1...3...1 0...0...1...3...1 0...0...0...1...3...1 0...0...0...0...1...3...1 0...0...0...0...0...1...3...1 ... - Philippe Deléham, Feb 08 2014 MATHEMATICA (* The function RiordanArray is defined in A256893. *) RiordanArray[1/Sqrt[1-6#+5#^2]&, (1-3#-Sqrt[1-6#+5#^2])/(2#)&, 10] // Flatten (* Jean-François Alcover, Jul 19 2019 *) CROSSREFS Sequence in context: A027516 A092808 A113955 * A111965 A110440 A135574 Adjacent sequences:  A110162 A110163 A110164 * A110166 A110167 A110168 KEYWORD easy,nonn,tabl AUTHOR Paul Barry, Jul 14 2005 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified October 20 07:23 EDT 2019. Contains 328252 sequences. (Running on oeis4.)