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 A037150 Fourier coefficients of Eisenstein series of degree 2 and weight 6 when evaluated at Gram(A_2)*z. 9
 1, 0, -1512, 44352, 449064, 6519744, 47263608, 257027904, 1115041032, 4093040448, 13000566096, 37057027392, 96945887304, 232758852480, 526296318912, 1128198915648, 2286101175624, 4451375005056, 8386154766360, 15131349955008, 26614555499952 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 REFERENCES J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, Third Ed., 1998. Helmut Klingen, Introductory Lectures on Siegel Modular Forms, Cambrifge, 1990, p. 123. LINKS N. J. A. Sloane, Table of n, a(n) for n = 0..100 N. J. A. Sloane, Notes on Two-dimensional Theta Series of Lattices (Notes on some joint work with Eric M. Rains), pages 96-115, circa Jun 08 1998, of N. J. A. Sloane's notebook "Lattices Volume 79". FORMULA x^12-72*x^6*y-1728*y^2, x = phi_0(z), y = Delta_12(z). Here phi_0(z) is the theta series of the A_2 lattice - see A004016, and Delta_12 is the 12-dimensional cusp form given in A007332. MAPLE # Maple code from N. J. A. Sloane, Dec 12 2020. Will also be useful for related sequences. # get standard theta series in Maple. First set max degree, maxd. maxd:=201: # get th2, th3, th4 = Jacobi theta constants out to degree maxd (Ref. Conway-Sloane, p. 102) temp0:=trunc(evalf(sqrt(maxd)))+2: a:=0: for i from -temp0 to temp0 do a:=a+q^( (i+1/2)^2): od: th2:=series(a, q, maxd); a:=0: for i from -temp0 to temp0 do a:=a+q^(i^2): od: th3:=series(a, q, maxd); th4:=series(subs(q=-q, th3), q, maxd); # get Dedekind eta function a:=q^(1/24) : for m from 1 to maxd do a:=a*(1-q^m); od: eta:=a; # get phi0 and phi1 (Ref. Conway-Sloane, p. 103) phi0:=series( subs(q=q^2, th2)*subs(q=q^6, th2)+subs(q=q^2, th3)*subs(q=q^6, th3), q, maxd ); phi1:=series( subs(q=q^2, th2)*subs(q=q^6, th3)+subs(q=q^2, th3)*subs(q=q^6, th2), q, maxd ); # get delta12 (Ref. Conway-Sloane, p. 204, where it is called Delta_6) delta12:=series((subs(q=q^3, eta)*eta)^6, q, maxd); delta12:=series(subs(q=q^2, delta12), q, maxd); # To get the present sequence: (Ref. Sloane notebook pages) x:=phi0; y:=delta12; w1:= x^12-72*x^6*y-1728*y^2; w1s:=series(w1, q, maxd); w2:=subs(q=sqrt(t), w1s); w3:=series(w2, t, 101); w4:=seriestolist(w3); # A037150 CROSSREFS Cf. A004016, A007332. Sequence in context: A255778 A236091 A239175 * A276291 A034601 A022059 Adjacent sequences:  A037147 A037148 A037149 * A037151 A037152 A037153 KEYWORD sign AUTHOR EXTENSIONS Entry revised by N. J. A. Sloane, Dec 12 2020 STATUS approved

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Last modified May 19 18:35 EDT 2022. Contains 353847 sequences. (Running on oeis4.)