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Expansion of eta(16z)^4*eta(4z)^2.
1

%I #13 Feb 22 2021 11:23:33

%S 1,-2,-1,2,-3,10,2,-8,-4,-14,7,4,18,-2,-13,14,1,14,-21,-4,-35,-14,28,

%T -6,7,38,39,-30,20,-36,-14,0,17,4,-49,14,-15,-22,-16,66,-39,-10,21,42,

%U 69,82,-18,-80,-28,-50,28,-70,-35,14,66,-56,41,-32,8,52,-77,42,3,36,60

%N Expansion of eta(16z)^4*eta(4z)^2.

%C Apparently this is the convolution square of A255252. - _R. J. Mathar_, Feb 22 2021

%H Johann Cigler, <a href="https://homepage.univie.ac.at/johann.cigler/preprints/losanitsch3.pdf">Some Pascal-like triangles</a>, 2018.

%H Ono and Skinner, <a href="https://doi.org/10.2307/121015">Fourier coefficients of half-integral weight modular forms modulo l</a>, Ann. Math., 147 (1998), 453-470.

%e q^3-2*q^7-1*q^11+2*q^15-3*q^19+...

%p nmax := 30;

%p eta := product(1-q^i,i=1..nmax) ; # eta=A010815

%p g := subs(q=q^4,eta)^4*eta^2 ;

%p g := taylor(g,q=0,nmax+1) ;

%p seq( coeftayl(g,q=0,i),i=0..nmax) ; # _R. J. Mathar_, Feb 22 2021

%Y Cf. A010815.

%K sign,easy

%O 0,2

%A _N. J. A. Sloane_.

%E More terms from _James A. Sellers_, Feb 09 2000