A380517 Absolute value of the minimum coefficient of (1 - x)^3 * (1 - x^2)^3 * (1 - x^3)^3 * ... * (1 - x^n)^3.

1, 3, 6, 15, 24, 50, 81, 186, 305, 561, 972, 1761, 3129, 5789, 10470, 19023, 33549, 62388, 113418, 205653, 366198, 674085, 1226181, 2211462, 3953679, 7287672, 13261764, 24005627, 42998125, 79033269, 143513301, 260061408, 465444889, 855436899, 1553736558, 2813222766, 5052061560, 9250734231

Offset

0,2

Links

Table of n, a(n) for n=0..37.

Maple

p:= proc(n) option remember;
     `if`(n=0, 1, expand(p(n-1)*(1-x^n)^3))
    end:
a:= n-> abs(min(coeffs(p(n)))):
seq(a(n), n=0..37);  # Alois P. Heinz, Jan 26 2025

Mathematica

Table[Min[CoefficientList[Product[(1 - x^k)^3, {k, 1, n}], x]], {n, 0, 37}] // Abs

Prog

(PARI) a(n) = abs(vecmin(Vec(prod(k=1, n, (1-x^k)^3)))); \\ Michel Marcus, Jan 26 2025

Crossrefs

Cf. A010816, A086394, A369709, A369711, A369983, A380499.

Sequence in context: A006639 A242757 A166448 * A192171 A281758 A280465

Adjacent sequences: A380514 A380515 A380516 * A380518 A380519 A380520

Keyword

nonn

Author

Ilya Gutkovskiy, Jan 26 2025

Status

approved