%I #15 Jul 22 2023 12:13:42
%S 0,1,0,0,0,0,0,0,0,-3,0,0,0,-6,0,0,0,-2,0,0,0,0,0,0,0,0,0,0,0,-10,0,0,
%T 0,0,0,0,0,2,0,0,0,10,0,0,0,0,0,0,0,-7,0,0,0,-14,0,0,0,0,0,0,0,-10,0,
%U 0,0,0,0,0,0,0,0,0,0,6,0,0,0,0,0,0,0,9,0,0,0,0,0,0,0,10
%N q-expansion of modular form (of weight 2 and level 800) associated with the curve y^2 = x^3 - 25x.
%H Robin Visser, <a href="/A221702/b221702.txt">Table of n, a(n) for n = 0..10000</a>
%H F. Q. Gouvea, <a href="https://www.jstor.org/stable/10.4169/amer.math.monthly.120.01.084">Review of "Elliptic Curves, Modular Forms and Their L-functions" by A. Lozano-Robledo</a>, Amer. Math. Monthly. 120 (Jan. 2013), 84-94.
%e q - 3*q^9 - 6*q^13 - 2*q^17 - 10*q^29 + 2*q^37 + 10*q^41 - 7*q^49 + ...
%o (Sage)
%o def a(n):
%o E = EllipticCurve([-25, 0])
%o return E.an(n) # _Robin Visser_, Jul 22 2023
%Y See A221705 for another version.
%K sign
%O 0,10
%A _N. J. A. Sloane_, Jan 22 2013
%E More terms from _Robin Visser_, Jul 22 2023