A380499 - OEIS

%I #8 Jan 25 2025 17:16:40

%S 1,2,2,6,4,12,8,24,19,44,36,78,74,148,156,286,322,556,682,1120,1448,

%T 2308,3072,4784,6538,10064,14001,21296,29928,45276,64032,96712,137520,

%U 207156,296236,444748,637812,956884,1373622,2062080,2968872,4450120,6422472,9616202,13894990,20802836

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

%p p:= proc(n) option remember;

%p      `if`(n=0, 1, expand(p(n-1)*(1-x^n)^2))

%p     end:

%p a:= n-> abs(min(coeffs(p(n)))):

%p seq(a(n), n=0..45);  # _Alois P. Heinz_, Jan 25 2025

%t Table[Min[CoefficientList[Product[(1 - x^k)^2, {k, 1, n}], x]], {n, 0, 45}] // Abs

%o (PARI) a(n) = abs(vecmin(Vec(prod(k=1, n, (1-x^k)^2)))); \\ _Michel Marcus_, Jan 25 2025

%Y Cf. A002107, A047653, A086394, A133871, A369710.

%K nonn

%O 0,2

%A _Ilya Gutkovskiy_, Jan 25 2025