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Number of partitions of n in which both even and odd squares occur with multiplicity 1. There is no restriction on the parts which are twice even squares.
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%I #8 Oct 18 2021 16:46:18

%S 1,1,0,0,1,1,0,0,1,2,1,0,1,2,1,0,2,3,1,0,2,3,1,0,2,5,3,0,2,5,3,0,3,6,

%T 4,1,4,7,4,1,4,9,6,1,4,10,7,1,5,12,9,2,6,13,9,2,6,15,12,3,6,17,14,3,8,

%U 20,16,4,9,21,17,5,10,25,22,7,10,27,24,7,12,32,28,9,14,34,30,10,15,39,37

%N Number of partitions of n in which both even and odd squares occur with multiplicity 1. There is no restriction on the parts which are twice even squares.

%F G.f.: Product_{k>0} ((1+x^(2k-1)^2)/(1-x^(2k)^2) = Product_{k>0} ((1+x^(2k-1)^2)*(1+x^(2k)^2)))/(1-x^2(2k)^2).

%e E.g. a(30) = 3 because we can write 30 as 25+4+1 = 16+9+4+1 = 8+8+9+4+1.

%p series(product((1+x^((2*k-1)^2)))/(1-x^((2*k)^2)),k=1..100),x=0,100);

%K nonn

%O 0,10

%A _Noureddine Chair_, Mar 01 2005