A281591 - OEIS

%I #10 Apr 15 2017 19:31:34

%S 3,5,6,5,7,6,8,7,8,8,8,8,9,9,9,9,10,10,10,10,10,10,11,11,10,11,12,11,

%T 11,12,11,12,12,12,12,13,12,13,12,13,13,13,13,13,13,13,14,13,14,13,14,

%U 14,14,14,14,14,15,14,15,14,15,14,15,15,15,15,15,15,16

%N First differences of A281590.

%H Vaclav Kotesovec, <a href="/A281591/b281591.txt">Table of n, a(n) for n = 1..2611</a>

%t nmax = 1000; A284896 = Rest[CoefficientList[Series[Product[1/(1 + x^k)^(k^2), {k, 1, nmax}], {x, 0, nmax}], x]]; csign = {1}; Do[If[(A284896[[n]] < 0 && A284896[[n+1]] >= 0) || (A284896[[n]] >= 0 && A284896[[n+1]] < 0), csign = Flatten[{csign, n + 1}]], {n, 1, Length[A284896] - 1}]; Differences[csign]

%Y Cf. A284896, A281590.

%K nonn

%O 1,1

%A _Vaclav Kotesovec_, Apr 14 2017