A128540 - OEIS

%I #11 Feb 18 2022 22:20:48

%S 1,1,1,0,2,2,0,0,3,3,0,0,0,5,5,0,0,0,0,8,8,0,0,0,0,0,13,13,0,0,0,0,0,

%T 0,21,21,0,0,0,0,0,0,0,34,34,0,0,0,0,0,0,0,0,55,55,0,0,0,0,0,0,0,0,0,

%U 89,89,0,0,0,0,0,0,0,0,0,0,144,144

%N Triangle A127647 * A097806, read by rows.

%C Row sums = A094895 starting (1, 2, 4, 6, 10, 16, 26, ...). A128541 = A097806 * A127647.

%H G. C. Greubel, <a href="/A128540/b128540.txt">Rows n = 1..100 of triangle, flattened</a>

%F A127646 * A097806 as infinite lower triangular matrices.

%e First few rows of the triangle:

%e   1;

%e   1, 1;

%e   0, 2, 2;

%e   0, 0, 3, 3;

%e   0, 0, 0, 5, 5;

%e   0, 0, 0, 0, 8, 8;

%e   ...

%t Table[If[k==n || k==n-1, Fibonacci[n], 0]], {n, 15}, {k, n}]//Flatten (* _G. C. Greubel_, Jul 11 2019 *)

%o (PARI) T(n,k) = if(k==n || k==n-1, fibonacci(n), 0); \\ _G. C. Greubel_, Jul 11 2019

%o (Magma) [k eq n select Fibonacci(n) else k eq n-1 select Fibonacci(n) else 0: k in [1..n], n in [1..15]]; // _G. C. Greubel_, Jul 11 2019

%o (Sage)

%o def T(n, k):

%o     if (k==n): return fibonacci(n)

%o     elif (k==n-1): return fibonacci(n)

%o     else: return 0

%o [[T(n, k) for k in (1..n)] for n in (1..15)] # _G. C. Greubel_, Jul 11 2019

%Y Cf. A127647, A097806, A128541.

%K nonn,tabl

%O 1,5

%A _Gary W. Adamson_, Mar 10 2007