Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%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