The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A306226 Triangle read by rows: T(n,k) = Sum_{i=0..n/2} C(n-i,i)*C(n-i,k-i)*C(n-1,i)  (0 <= k <= n). 0
 1, 1, 1, 1, 3, 2, 1, 7, 11, 5, 1, 13, 36, 37, 13, 1, 21, 92, 160, 123, 35, 1, 31, 200, 520, 655, 401, 96, 1, 43, 387, 1405, 2575, 2541, 1293, 267, 1, 57, 686, 3325, 8295, 11711, 9492, 4131, 750, 1, 73, 1136, 7112, 23128, 43736, 50148, 34476, 13107, 2123, 1, 91, 1782, 14040, 57708, 140112, 212856, 205332, 122535, 41353, 6046 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 0,5 LINKS FORMULA G.f.: (x*y+x+1)/(2*sqrt((-x*y-x+1)^2-4*x*y*(x*y+x)))+1/2. EXAMPLE 1; 1, 1; 1, 3, 2; 1, 7, 11, 5; 1, 13, 36, 37, 13; 1, 21, 92, 160, 123, 35; PROG (Maxima) T(n, k):=sum(binomial(n-i, i)*binomial(n-i, k-i)*binomial(n-1, i), i, 0, n/2); CROSSREFS Cf. A123160. Cf. A005773 (right diagonal). Sequence in context: A122832 A056151 A134436 * A186370 A163626 A028246 Adjacent sequences:  A306223 A306224 A306225 * A306227 A306228 A306229 KEYWORD nonn,tabl AUTHOR Vladimir Kruchinin, Feb 16 2019 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 May 6 16:14 EDT 2021. Contains 343586 sequences. (Running on oeis4.)