A141290 Triangle read by rows, descending antidiagonals of a (1, 3, 5, ...) * (1, 4, 16, ...) multiplication table.
1, 3, 4, 5, 12, 16, 7, 20, 48, 64, 9, 28, 80, 192, 256, 11, 36, 112, 320, 768, 1024, 13, 44, 144, 448, 1280, 3072, 4096, 15, 52, 176, 576, 1792, 5120, 12288, 16384, 17, 60, 208, 704, 2304, 7168, 20480, 49152, 65536, 19, 68, 240, 832, 2816, 9216, 28672, 81920, 196608, 262144
Offset: 1
Examples
Given the multiplication table (1, 3, 5, ...) * (1, 4, 16, ...); i.e., odd numbers as column headings, powers of 4 along the left border: 1, 3, 5, 7, ... 4, 12, 20, 28, ... 16, 48, 80, 112, ... 64, 192, 320, 448, ... ... Rows of the triangle = descending antidiagonals of the array, getting: 1; 3, 4; 5, 12, 16; 7, 20, 48, 64; 9, 28, 80, 192, 256; 11, 36, 112, 320, 768, 1024; 13, 44, 144, 448, 1280, 3072, 4096; 15, 52, 176, 576, 1792, 5120, 122288, 16384; ...
Programs
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Mathematica
A[n_,k_]:=(2k-1)*4^(n-1); Table[A[k,n-k+1],{n,10},{k,n}]//Flatten (* Stefano Spezia, May 21 2024 *)
Formula
From Stefano Spezia, May 21 2024: (Start)
G.f. as array: x*y*(1 + y)/((1 - 4*x)*(1 - y)^2).
E.g.f. as array: (exp(4*x) - 1)*(exp(y)*(1 - 2*y) - 1)/4. (End)
Extensions
a(14), a(36) corrected by Peter Munn, Aug 27 2019
Comments