A134392 A077028 * A000012, that is Rascal's triangle (as matrix) multiplied by a lower triangular matrix of ones (main diagonal of ones included).
1, 2, 1, 4, 3, 1, 8, 7, 4, 1, 15, 14, 10, 5, 1, 26, 25, 20, 13, 6, 1, 42, 41, 35, 26, 16, 7, 1, 64, 63, 56, 45, 32, 19, 8, 1, 93, 92, 84, 71, 55, 38, 22, 9, 1, 130, 129, 120, 105, 86, 65, 44, 25, 10, 1, 176, 175, 165, 148, 126, 101, 75, 50, 28, 11, 1
Offset: 1
Examples
First few rows of the triangle: 1; 2, 1; 4, 3, 1; 8, 7, 4, 1; 15, 14, 10, 5, 1; 26, 25, 20, 13, 6, 1; 42, 41, 35, 26, 16, 7, 1; ...
Programs
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Mathematica
rows = 11; R[n_, k_] /; k <= n := k (n - k) + 1; R[0, 0] = 1; R[, ] = 0; MR = Table[R[n, k], {n, 0, rows-1}, {k, 0, rows-1}]; MB = Table[Boole[0 <= k <= n], {n, 0, rows-1}, {k, 0, rows -1}]; T = MR.MB; Table[T[[n, k]], {n, 1, rows}, {k, 1, n}] // Flatten (* Jean-François Alcover, Apr 01 2020 *)
Formula
Extensions
Typos corrected by Jean-François Alcover, Apr 01 2020
Comments