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

 

Logo

Thanks to everyone who made a donation during our annual appeal!
To see the list of donors, or make a donation, see the OEIS Foundation home page.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A110682 A convolution triangle of numbers based on A027307. 1

%I

%S 1,2,1,10,4,1,66,24,6,1,498,172,42,8,1,4066,1360,326,64,10,1,34970,

%T 11444,2706,536,90,12,1,312066,100520,23526,4672,810,120,14,1,2862562,

%U 911068,211546,42024,7410,1156,154,16,1

%N A convolution triangle of numbers based on A027307.

%C Triangle T(n,k) for A(x)^k = Sum_{n>=k} T(n,k)*x^n, where o.g.f. A(x) satisfies A(x) = (1+x*A(x)^2)/(1-x*A(x)^2). - _Vladimir Kruchinin_, Mar 16 2011

%H G. C. Greubel, <a href="/A110682/b110682.txt">Table of n, a(n) for the first 100 rows, flattened</a>

%H Vladimir Kruchinin, D. V. Kruchinin, <a href="http://arxiv.org/abs/1103.2582">Composita and their properties</a>, arXiv:1103.2582 [math.CO], 2011-2013.

%F T(0, 0) = 1; T(n, k) = 0 if k<0 or if k>n; T(n, k) = Sum_{j, j>=0} T(n-1, k-1+j)*A006318(j).

%F Sum_{k, k>=0} T(n, k) = A108442(n+1).

%F T(n,k) = k/(2*n-k)*Sum_{i=0,n-k} binomial(2*n-k,n-k-i)*binomial(2*n-k+i-1,2*n-k-1), n >= k > 0. - _Vladimir Kruchinin_, Mar 16 2011

%t T[n_, k_] := (k/(2*n - k))*Sum[Binomial[2*n - k, n - k - j]*Binomial[2*n - k + j - 1, 2*n - k - 1], {j, 0, n - k}]; Table[T[n, k], {n, 0, 25}, {k, 1, n}] // Flatten (* _G. C. Greubel_, Sep 05 2017 *)

%o (PARI) for(n=0,25, for(k=1,n, print1((k/(2*n-k))*sum(i=0,n-k, binomial(2*n-k,n-k-i)*binomial(2*n-k+i-1,2*n-k-1)), ", "))) \\ _G. C. Greubel_, Sep 05 2017

%Y Columns: A027307, A032349, A033296.

%K nonn,tabl

%O 0,2

%A _Philippe Deléham_, Sep 15 2005

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.

License Agreements, Terms of Use, Privacy Policy. .

Last modified January 20 11:06 EST 2020. Contains 331083 sequences. (Running on oeis4.)