A204206 Triangle based on (1,3/2,2) averaging array.

3, 5, 7, 9, 12, 15, 17, 21, 27, 31, 33, 38, 48, 58, 63, 65, 71, 86, 106, 121, 127, 129, 136, 157, 192, 227, 248, 255, 257, 265, 293, 349, 419, 475, 503, 511, 513, 522, 558, 642, 768, 894, 978, 1014, 1023, 1025, 1035, 1080, 1200, 1410, 1662, 1872

Offset: 1

Author

Clark Kimberling, Jan 12 2012

Keywords

• nonn
• tabl

Comments

See A204201 for a discussion and guide to other averaging arrays.

Examples

			First six rows:
3
5...7
9...12...15
17..21...27...31
33..38...48...58...63
65..71...86...106..121..127
		

Crossrefs

Cf. A204201.

Programs

Mathematica

a = 1; r = 3/2; b = 2;
t[1, 1] = r;
t[n_, 1] := (a + t[n - 1, 1])/2;
t[n_, n_] := (b + t[n - 1, n - 1])/2;
t[n_, k_] := (t[n - 1, k - 1] + t[n - 1, k])/2;
u[n_] := Table[t[n, k], {k, 1, n}]
Table[u[n], {n, 1, 5}]    (* averaging array *)
u = Table[3 (1/2) (1/r) 2^n*u[n], {n, 1, 12}];
TableForm[u]   (* A204206 triangle *)
Flatten[u]     (* A204206 sequence *)

Formula

From Philippe Deléham, Dec 24 2013: (Start)

T(n,n) = A000225(n+1).

Sum_{k=1..n} T(n,k) = A167667(n).

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)=3, T(2,1)=5, T(2,2)=7, T(n,k)=0 if k<1 or if k>n. (End)