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 A065099 Weight 5 level 11 cusp form with complex multiplication by Q(sqrt(11)) and trivial character. 5
 1, 0, 7, 16, -49, 0, 0, 0, -32, 0, 121, 112, 0, 0, -343, 256, 0, 0, 0, -784, 0, 0, 167, 0, 1776, 0, -791, 0, 0, 0, -553, 0, 847, 0, 0, -512, -2113, 0, 0, 0, 0, 0, 0, 1936, 1568, 0, -1918, 1792, 2401, 0, 0, 0, -718, 0, -5929, 0, 0, 0, 4487, -5488, 0, 0, 0, 4096 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS This is a member of an infinite family of odd weight level 11 multiplicative modular forms. g_1 = A035179, g_3 = A129522, g_5 = A065099, g_7 = A138661. - Michael Somos, Jun 07 2015 LINKS K. Ono, On the Circular Summation of the Eleventh Powers of Ramanujan's Theta Function, Journal of Number Theory, Volume 76, Issue 1, May 1999, Pages 62-65. G. Shimura, On elliptic curves with complex multiplication as factors of the Jacobians of modular function fields, Nagoya Math. J. 43 (1971) p. 205. FORMULA G.f. is a period 1 Fourier series which satisfies f(-1 / (11 t)) = 11^(5/2) (t/i)^5 f(t) where q = exp(2 Pi i t). - Michael Somos, Jun 08 2007 a(n) is multiplicative with a(11^e) = 121^e, a(p^e) = (1 + (-1)^e) / 2 * p^(2*e) if p == 2, 6, 7, 8, 10 (mod 11), a(p^e) = a(p) * a(p^(e-1)) - p^4 * a(p^(e-2)) if p == 1, 3, 4, 5, 9 (mod 11) where a(p) = y^4 - 4 * p*y^2 + 2 * p^2 and 4*p = y^2 + 11 * x^2. - Michael Somos, Jun 08 2007 EXAMPLE G.f. = q + 7*q^3 + 16*q^4 - 49*q^5 - 32*q^9 + 121*q^11 + 112*q^12 - 343*q^15 + ... MATHEMATICA a[ n_] := SeriesCoefficient[ With[{F1 = (QPochhammer[ q] QPochhammer[ q^11])^2, F2 = (QPochhammer[ q^2] QPochhammer[ q^22])^2, F3 = (QPochhammer[ q^2] QPochhammer[ q^22])^3, F4 = (QPochhammer[ q^4] QPochhammer[ q^44])^2}, (F1^4 + 8 q F1^3 F2 + 32 q^2 F1^2 F2^2 + 88 q^3 F1 F2^3 + 64 q^4 F2^4 + 96 q^6 F4 F2^3 + 128 q^5 F1 F4 (F2^2 + q^2 F2 F4 + q^4 F4^2)) / F3], {q, 0, n}]; (* Michael Somos, Jun 07 2015 *) PROG (PARI) { B(N, a, x, y, x2, y2)= a=vector(N); for (x=0, floor(sqrt(4*N)), for (y=0, floor(sqrt(4*N/11)), x2=x*x; y2=y*y; n=(x2+11*y2); if (n%4==0 && n<=4*N && n>0, w=(2*x2*x2-132*x2*y2+242*y2*y2)/32; a[n/4]+=w; if (x*y !=0, a[n/4]+=w)))); a } (PARI) {a(n) = my(A, p, e, x, y, a0, a1); if( n<1, 0, A = factor(n); prod( k=1, matsize(A)[1], [p, e] = A[k, ]; if( p==11, 121^e, kronecker( -11, p)==-1, if( e%2, 0, p^(2*e)), for( x=1, sqrtint(4*p\11), if( issquare(4*p - 11*x^2, &y), break)); y = y^4 - 4 * p*y^2 + 2 * p^2; a0=1; a1=y; for( i=2, e, x=y*a1 - p^4*a0; a0=a1; a1=x); a1)))}; /* Michael Somos, Jun 08 2007 */ (PARI) {a(n) = my(A, F1, F2, F4); if( n<1, 0, n--; A = x * O(x^n); F1 = (eta(x + A) * eta(x^11 + A))^2; F2 = (eta(x^2 + A) * eta(x^22 + A))^2; F4 = (eta(x^4 + A) * eta(x^44 + A))^2; polcoeff( (F1^4 + 8 * x * F1^3*F2 + 32 * x^2 * F1^2*F2^2 + 88 * x^3 * F1*F2^3 + 64 * x^4 * F2^4 + 96 * x^6 * F4*F2^3 + 128 * x^5 * F1*F4 * (F2^2 + x^2 * F2*F4 + x^4 * F4^2)) / (eta(x^2 + A) * eta(x^22 + A))^3, n))}; /* Michael Somos, Jun 08 2007 */ (PARI) {a(n) = if( n<1, 0, n*=4; sum( y=0, sqrtint(n\11), if( issquare( n - 11 * y^2), if( (n > 11*y^2) && y, 2, 1) * (n^2 - 88 * n*y^2 + 968 * y^4) / 16)))}; /* Michael Somos, Jun 08 2007 */ (MAGMA) A := Basis( CuspForms( Gamma1(11), 5), 71); A[1] + 7*A[3] + 16*A[4] - 49*A[5] - 32*A[9] + 121*A[11] + 112*A[12] - 343*A[15]; /* Michael Somos, Aug 26 2015 */ CROSSREFS Cf. A035179, A129522, A138661. Sequence in context: A154141 A173661 A152530 * A001345 A225128 A056613 Adjacent sequences:  A065096 A065097 A065098 * A065100 A065101 A065102 KEYWORD sign,mult AUTHOR Kok Seng Chua (chuaks(AT)ihpc.nus.edu.sg), Nov 20 2001 STATUS approved

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Last modified September 26 01:25 EDT 2020. Contains 337346 sequences. (Running on oeis4.)