This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A332332 #40 Sep 30 2023 17:23:52
%S A332332 1,1,-1,-1,-2,-1,4,-3,1,-2,1,1,-2,4,2,-1,-2,1,0,2,-4,1,8,3,-1,-2,-1,
%T A332332 -4,-6,2,-8,5,-1,-2,-8,-1,6,0,2,6,-2,-4,0,-1,-2,8,8,1,9,-1,2,2,6,-1,
%U A332332 -2,-12,0,-6,-4,-2,6,-8,4,7,4,-1,-4,2,-8,-8,0,-3,-14,6
%N A332332 Coefficients of L-series for elliptic curve "33a1": y^2 + x*y = x^3 + x^2 - 11*x.
%H A332332 Robin Visser, <a href="/A332332/b332332.txt">Table of n, a(n) for n = 1..10000</a>
%H A332332 LMFDB, <a href="https://www.lmfdb.org/EllipticCurve/Q/33/a/2">Elliptic Curve with LMFDB label 33.a2 (Cremona label 33a1)</a>
%F A332332 Expansion of eta(q)^2*eta(q^11)^2 + 3*eta(q)*eta(q^3)*eta(q^11)*eta(q^33) + 3*eta(q^3)^2*eta(q^33)^2 in powers of q.
%F A332332 G.f. is a period 1 Fourier series which satisfies f(-1 / (33 t)) = 33 (t/i)^2 f(t) where q = exp(2 Pi i t).
%F A332332 a(n) is multiplicative with a(3^n) = (-1)^n, a(11^n) = 1. a(2^n) = A107920(n+1). a(7^n) = A168175(n).
%e A332332 G.f. = x + x^2 - x^3 - x^4 - 2*x^5 - x^6 + 4*x^7 - 3*x^8 + x^9 + ...
%o A332332 (PARI) {a(n) = if( n<1, 0, ellak( ellinit( [1, 1, 0, -11, 0], 1), n))};
%o A332332 (PARI) {a(n) = my(A, t1, t3); if( n<1, 0, n--; A = x * O(x^n); t1 = eta(x + A) * eta(x^11 + A); t3 = x * eta(x^3 + A) * eta(x^33 + A); polcoeff( t1^2 + 3*t1*t3 + 3*t3^2, n))};
%o A332332 (Magma) A := Basis( ModularForms( Gamma0(33), 2), 75); A[2] + A[3] - A[4] - A[5] - A[6];
%o A332332 (Sage)
%o A332332 def a(n):
%o A332332 return EllipticCurve("33a1").an(n) # _Robin Visser_, Sep 30 2023
%Y A332332 Cf. A107920, A168175.
%K A332332 sign,mult
%O A332332 1,5
%A A332332 _Michael Somos_, Feb 23 2020