The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A097084 Triangle, read by rows, where the n-th diagonal equals the n-th row transformed by triangle A008459 (squared binomial coefficients). 2

%I #14 Jun 13 2017 22:09:51

%S 1,1,1,1,2,1,1,3,5,1,1,4,10,10,1,1,5,18,28,17,1,1,6,27,74,69,26,1,1,7,

%T 39,137,245,151,37,1,1,8,52,236,586,676,298,50,1,1,9,68,372,1194,2126,

%U 1634,540,65,1,1,10,85,552,2322,5152,6620,3578,913,82,1,1,11,105,777,3954,12002,19292,18082,7249,1459,101,1

%N Triangle, read by rows, where the n-th diagonal equals the n-th row transformed by triangle A008459 (squared binomial coefficients).

%C Row sums form A097085.

%H Alois P. Heinz, <a href="/A097084/b097084.txt">Rows n = 0..140, flattened</a>

%F T(n,k) = Sum_{j=0..k} T(n-k,j)*C(k,j)^2.

%e T(8,3) = 236 = (1)*1^2 + (5)*3^2 + (18)*3^2 + (28)*1^2

%e = Sum_{j=0..3} T(5,j)*C(3,j)^2.

%e Rows begin:

%e [1],

%e [1,1],

%e [1,2,1],

%e [1,3,5,1],

%e [1,4,10,10,1],

%e [1,5,18,28,17,1],

%e [1,6,27,74,69,26,1],

%e [1,7,39,137,245,151,37,1],

%e [1,8,52,236,586,676,298,50,1],...

%p T:= proc(n, k) option remember;

%p `if`(n=k or k=0, 1, `if`(k<0 or k>n, 0,

%p add(T(n-k, j)*binomial(k, j)^2, j=0..k)))

%p end:

%p seq(seq(T(n,k), k=0..n), n=0..12); # _Alois P. Heinz_, Oct 30 2015

%t T[_, 0] = 1; T[n_, n_] = 1; T[n_, k_] /; 0 < k < n := T[n, k] = Sum[T[n - k, j]*Binomial[k, j]^2, {j, 0, k}]; T[_, _] = 0;

%t Table[T[n, k], {n, 0, 12}, {k, 0, n}] // Flatten (* _Jean-François Alcover_, May 24 2016 *)

%o (PARI) T(n,k)=if(n<k || k<0,0,if(n==k || k==0,1,sum(j=0,n-k,T(n-k,j)*binomial(k,j)^2)))

%Y Cf. A097085, A008459.

%K nonn,tabl

%O 0,5

%A _Paul D. Hanna_, Jul 23 2004

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 15 19:42 EDT 2024. Contains 372549 sequences. (Running on oeis4.)