A352499 Irregular triangle read by rows: T(n,k) is the sum of all parts of the partition of n into consecutive parts that contains 2*k-1 parts, and the first element of the column k is in row A000384(k).
1, 2, 3, 4, 5, 6, 6, 7, 0, 8, 0, 9, 9, 10, 0, 11, 0, 12, 12, 13, 0, 14, 0, 15, 15, 15, 16, 0, 0, 17, 0, 0, 18, 18, 0, 19, 0, 0, 20, 0, 20, 21, 21, 0, 22, 0, 0, 23, 0, 0, 24, 24, 0, 25, 0, 25, 26, 0, 0, 27, 27, 0, 28, 0, 0, 28, 29, 0, 0, 0, 30, 30, 30, 0, 31, 0, 0, 0, 32, 0, 0, 0
Offset: 1
Examples
Triangle begins: 1; 2; 3; 4; 5; 6, 6; 7, 0; 8, 0; 9, 9; 10, 0; 11, 0; 12, 12; 13, 0; 14, 0; 15, 15, 15; 16, 0, 0; 17, 0, 0; 18, 18, 0; 19, 0, 0; 20, 0, 20; 21, 21, 0; 22, 0, 0; 23, 0, 0; 24, 24, 0; 25, 0, 25; 26, 0, 0; 27, 27, 0; 28, 0, 0, 28; ... For n = 21 the partitions of 21 into on odd number of consecutive parts are [21] and [8, 7, 6], so T(21,1) = 1 and T(21,2) = 8 + 7 + 6 = 21. There is no partition of 21 into five consecutive parts so T(21,3) = 0.
Links
- Paolo Xausa, Table of n, a(n) for n = 1..10490 (rows 1..800 of triangle, flattened).
Crossrefs
Programs
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Mathematica
A352499[rowmax_]:=Table[Boole[Divisible[n,2k-1]]n,{n,rowmax},{k,Floor[(Sqrt[8n+1]+1)/4]}];A352499[50] (* Paolo Xausa, Apr 12 2023 *)
Formula
T(n,k) = n*A351824(n,k).
T(n,k) = n*[(2*k-1)|n], where 1 <= k <= floor((sqrt(8*n+1)+1)/4) and [] is the Iverson bracket. - Paolo Xausa, Apr 12 2023
Comments