login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Triangle based on (0,2/3,1) averaging array.
2

%I #10 Dec 24 2013 01:52:27

%S 2,2,5,2,7,11,2,9,18,23,2,11,27,41,47,2,13,38,68,88,95,2,15,51,106,

%T 156,183,191,2,17,66,157,262,339,374,383,2,19,83,223,419,601,713,757,

%U 767,2,21,102,306,642,1020,1314,1470,1524,1535,2,23,123,408,948

%N Triangle based on (0,2/3,1) averaging array.

%C See A204201 for a discussion of averaging arrays and related triangles

%F From _Philippe Deléham_, Dec 24 2013: (Start)

%F T(n,n) = A055010(n) = A083329(n) = A153893(n-1).

%F Sum_{k=1..n} T(n,k) = A066373(n+1).

%F T(n,k) = T(n-1,k)+3*T(n-1,k-1)-2*T(n-2,k-1)-2*T(n-2,k-2), T(1,1)=2, T(2,1)=2, T(2,2)=5, T(n,k)=0 if k<1 or if k>n. (End)

%e First six rows:

%e 2

%e 2...5

%e 2...7....11

%e 2...9....18...23

%e 2...11...27...41...47

%e 2...13...38...68...88..95

%t a = 0; r = 2/3; b = 1;

%t t[1, 1] = r;

%t t[n_, 1] := (a + t[n - 1, 1])/2;

%t t[n_, n_] := (b + t[n - 1, n - 1])/2;

%t t[n_, k_] := (t[n - 1, k - 1] + t[n - 1, k])/2;

%t u[n_] := Table[t[n, k], {k, 1, n}]

%t Table[u[n], {n, 1, 5}] (* averaging array *)

%t u = Table[(1/r) 2^n*u[n], {n, 1, 12}];

%t TableForm[u] (* A204202 triangle *)

%t Flatten[u] (* A204202 sequence *)

%Y Cf. A204201.

%K nonn,tabl

%O 1,1

%A _Clark Kimberling_, Jan 12 2012