A135299 Pascal's triangle, but the last element of the row is the sum of all the previous terms.
1, 1, 2, 1, 3, 8, 1, 4, 11, 32, 1, 5, 15, 43, 128, 1, 6, 20, 58, 171, 512, 1, 7, 26, 78, 229, 683, 2048, 1, 8, 33, 104, 307, 912, 2731, 8192, 1, 9, 41, 137, 411, 1219, 3643, 10923, 32768, 1, 10, 50, 178, 548, 1630, 4862, 14566, 43691, 131072
Offset: 0
Examples
T(2,1) = T(1,0) + T(1,1) = 1 + 2 = 3; T(2,2) = T(0,0) + T(1,0) + T(1,1) + T(2,0) + T(2,1) = 1 + 1 + 2 + 1 + 3 = 8. From _G. C. Greubel_, Oct 09 2016: (Start) The triangle is: 1; 1, 2; 1, 3, 8; 1, 4, 11, 32; 1, 5, 15, 43, 128; 1, 6, 20, 58, 171, 512; ... (End)
Links
- G. C. Greubel, Table of n, a(n) for the first 25 rows
Programs
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Mathematica
T[0, 0] := 1; T[n_, 0] := 1; T[n_, k_] := T[n - 1, k] + T[n - 1, k - 1]; T[n_, n_] := 2^(2*n - 1); Table[T[n, k], {n, 0, 5}, {k, 0, n}] (* G. C. Greubel, Oct 09 2016 *)
Formula
T(0,0) = 1;
T(n,0) = 1;
T(n,k) = T(n-1, k-1) + T(n-1, k) if k < n;
T(n,n) = (Sum_{j=0..n-1} Sum_{i=0..j} T(j,i)) + Sum_{i=0..n-1} T(n,i) [i.e., sum of all earlier terms of the triangle].
T(n,n) = (4^n)/2 for n > 0;
T(n,n) = 2*Sum_{i=0..n-1} T(n,i).