A369987 - OEIS

%I #13 Feb 07 2024 19:22:13

%S 1,1,1,1,1,1,2,2,2,3,3,4,7,7,7,8,11,18,23,28,32,40,55,58,83,118,128,

%T 171,210,327,439,555,843,1009,1580,2254,3224,4703,6999,4573,6860,7760,

%U 12563,15626,24451,33788,48806,51522,84103,120853,171206,312262,306080,464713,657411,892342

%N Maximum of the absolute value of the coefficients of (1 - x) * (1 - x^8) * (1 - x^27) * ... * (1 - x^(n^3)).

%t Table[Max[Abs[CoefficientList[Product[(1 - x^(k^3)), {k, 1, n}], x]]], {n, 0, 43}]

%o (PARI) a(n) = vecmax(apply(abs, Vec(prod(i=1, n, (1-x^(i^3)))))); \\ _Michel Marcus_, Feb 07 2024

%o (Python)

%o from collections import Counter

%o def A369987(n):

%o     c = {0:1}

%o     for k in range(1,n+1):

%o         m, b = k**3, Counter(c)

%o         for j in c:

%o             b[j+m] -= c[j]

%o         c = b

%o     return max(map(abs,c.values())) # _Chai Wah Wu_, Feb 07 2024

%Y Cf. A000578, A160089, A279484, A359319, A369764, A369986.

%K nonn

%O 0,7

%A _Ilya Gutkovskiy_, Feb 07 2024

%E More terms from _Michel Marcus_, Feb 07 2024