A340583 Triangle read by rows: T(n,k) = A002865(n-k)*A000203(k), 1 <= k <= n.
1, 0, 3, 1, 0, 4, 1, 3, 0, 7, 2, 3, 4, 0, 6, 2, 6, 4, 7, 0, 12, 4, 6, 8, 7, 6, 0, 8, 4, 12, 8, 14, 6, 12, 0, 15, 7, 12, 16, 14, 12, 12, 8, 0, 13, 8, 21, 16, 28, 12, 24, 8, 15, 0, 18, 12, 24, 28, 28, 24, 24, 16, 15, 13, 0, 12, 14, 36, 32, 49, 24, 48, 16, 30, 13, 18, 0, 28
Offset: 1
Examples
Triangle begins: 1; 0, 3; 1, 0, 4; 1, 3, 0, 7; 2, 3, 4, 0, 6; 2, 6, 4, 7, 0, 12; 4, 6, 8, 7, 6, 0, 8; 4, 12, 8, 14, 6, 12, 0, 15; 7, 12, 16, 14, 12, 12, 8, 0, 13; 8, 21, 16, 28, 12, 24, 8, 15, 0, 18; 12, 24, 28, 28, 24, 24, 16, 15, 13, 0, 12; 14, 36, 32, 49, 24, 48, 16, 30, 13, 18, 0, 28; ... For n = 6 the calculation of every term of row 6 is as follows: -------------------------- k A000203 T(6,k) -------------------------- 1 1 * 2 = 2 2 3 * 2 = 6 3 4 * 1 = 4 4 7 * 1 = 7 5 6 * 0 = 0 6 12 * 1 = 12 . A002865 -------------------------- The sum of row 6 is 2 + 6 + 4 + 7 + 0 + 12 = 31, equaling A138879(6).
Crossrefs
Programs
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Mathematica
A340583[n_, k_] := (PartitionsP[n - k] - PartitionsP[(n - k) - 1])* DivisorSigma[1, k]; Table[A340583[n, k], {n, 1, 12}, {k, 1, n}] // Flatten (* Robert P. P. McKone, Jan 25 2021 *)
Comments