A292189 Square array A(n,k), n>=0, k>=0, read by antidiagonals, where column k is the expansion of Product_{j>=1} (1 + j^k*x^j).
1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 1, 1, 4, 5, 2, 1, 1, 8, 13, 7, 3, 1, 1, 16, 35, 25, 15, 4, 1, 1, 32, 97, 91, 77, 25, 5, 1, 1, 64, 275, 337, 405, 161, 43, 6, 1, 1, 128, 793, 1267, 2177, 1069, 393, 64, 8, 1, 1, 256, 2315, 4825, 11925, 7313, 3799, 726, 120, 10
Offset: 0
Examples
Square array begins: 1, 1, 1, 1, 1, ... 1, 1, 1, 1, 1, ... 1, 2, 4, 8, 16, ... 2, 5, 13, 35, 97, ... 2, 7, 25, 91, 337, ...
Links
- Alois P. Heinz, Rows n = 0..150, flattened
Crossrefs
Programs
-
Maple
b:= proc(n, i, k) option remember; (m-> `if`(m
n, 0, i^k*b(n-i, i-1, k)))))(i*(i+1)/2) end: A:= (n, k)-> b(n$2, k): seq(seq(A(n, d-n), n=0..d), d=0..14); # Alois P. Heinz, Sep 11 2017 -
Mathematica
m = 14; col[k_] := col[k] = Product[1 + j^k*x^j, {j, 1, m}] + O[x]^(m+1) // CoefficientList[#, x]&; A[n_, k_] := col[k][[n+1]]; Table[A[n, d-n], {d, 0, m}, {n, 0, d}] // Flatten (* Jean-François Alcover, Feb 11 2021 *)