cp's OEIS Frontend

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.

Showing 1-3 of 3 results.

A107498 Theta series of quadratic form with Gram matrix [ 4, -1, 1, 1; -1, 10, 3, 3; 1, 3, 10, -3; 1, 3, -3, 88].

Original entry on oeis.org

1, 0, 2, 0, 0, 4, 4, 4, 6, 0, 0, 8, 0, 2, 0, 8, 0, 0, 6, 8, 12, 8, 0, 0, 12, 0, 6, 0, 8, 0, 0, 12, 14, 8, 8, 0, 0, 4, 0, 8, 0, 16, 0, 0, 24, 16, 16, 24, 0, 0, 26, 0, 14, 0, 36, 0, 0, 20, 24, 28, 44, 0, 0, 32, 0, 12, 0, 20, 0, 0, 40, 36, 58, 16, 0, 0, 52, 0, 24
Offset: 0

Views

Author

N. J. A. Sloane, May 28 2005

Keywords

Comments

G.f. is theta_2 in the Parry 1979 reference on page 166. This theta series is an element of the space of modular forms on Gamma_0(169) of weight 2 and dimension 21. - Andy Huchala, May 13 2023

Examples

			G.f. = 1 + 2*q^4 + 4*q^10 + 4*q^12 + ...
		

Crossrefs

Programs

  • Magma
    prec := 60;
    ls := [[4, -1, 1, 1], [-1, 10, 3, 3], [1, 3, 10, -3], [1, 3, -3, 88]];
    S := Matrix(ls);
    L := LatticeWithGram(S);
    M := ThetaSeriesModularFormSpace(L);
    B := Basis(M, prec);
    T := ThetaSeries(L, 48);
    coeffs := [Coefficients(T)[2*i-1] : i in [1..23]];
    Coefficients(&+[coeffs[i]*B[i] :i in [1..13]]+&+[coeffs[i+1]*B[i] :i in [14..19]] + coeffs[22]*B[20] + coeffs[23]*B[21]); // Andy Huchala, May 13 2023

Extensions

Name clarified and more terms from Andy Huchala, May 13 2023

A107497 Theta series of quadratic form with Gram matrix [ 2, 1, 1, 1; 1, 20, 7, 7; 1, 7, 20, 7; 1, 7, 7, 46].

Original entry on oeis.org

1, 2, 0, 0, 2, 0, 0, 0, 0, 2, 8, 0, 8, 2, 4, 0, 10, 4, 0, 0, 0, 0, 12, 4, 0, 6, 6, 12, 0, 8, 20, 0, 0, 0, 0, 16, 22, 0, 24, 8, 24, 0, 32, 20, 0, 0, 0, 0, 36, 14, 0, 20, 14, 16, 0, 24, 32, 0, 0, 0, 0, 20, 28, 0, 30, 12, 44, 0, 24, 24, 0, 0, 0, 0, 28, 44, 0, 32
Offset: 0

Views

Author

N. J. A. Sloane, May 28 2005

Keywords

Comments

G.f. is theta_1 in the Parry 1979 reference on page 166. This theta series is an element of the space of modular forms on Gamma_0(169) of weight 2 and dimension 21. - Andy Huchala, May 13 2023

Examples

			G.f. = 1 + 2*q^2 + 2*q^8 + 2*q^18 + ...
		

Crossrefs

Programs

  • Magma
    prec := 60;
    ls := [[2,1,1,1],[1,20,7,7],[1,7,20,7],[1,7,7,46]];
    S := Matrix(ls);
    L := LatticeWithGram(S);
    M := ThetaSeriesModularFormSpace(L);
    B := Basis(M, prec);
    T := ThetaSeries(L,44);
    coeffs := [Coefficients(T)[2*i-1] : i in [1..23]];
    Coefficients(&+[coeffs[i]*B[i] :i in [1..13]]+&+[coeffs[i+1]*B[i] :i in [14..19]] + coeffs[22]*B[20] + coeffs[23]*B[21]); // Andy Huchala, May 13 2023

Extensions

Name clarified and more terms from Andy Huchala, May 13 2023

A045399 Primes congruent to {0, 3, 5, 6} mod 7.

Original entry on oeis.org

3, 5, 7, 13, 17, 19, 31, 41, 47, 59, 61, 73, 83, 89, 97, 101, 103, 131, 139, 157, 167, 173, 181, 199, 223, 227, 229, 241, 251, 257, 269, 271, 283, 293, 307, 311, 313, 349, 353, 367, 383, 397, 409, 419, 433, 439
Offset: 1

Views

Author

Keywords

Comments

Primes p such that A140686(p) = 0. - Michael Somos, Feb 12 2011
Primes (along with 2) which cannot be written in the form a^2 + 7*b^2, where a > 0, b > 0. - V. Raman, Sep 08 2012

Crossrefs

Cf. A000040.

Programs

  • Magma
    [ p: p in PrimesUpTo(600) | p mod 7 in {0, 3, 5, 6} ]; // Vincenzo Librandi, Aug 12 2012
  • Mathematica
    Select[Prime[Range[300]],MemberQ[{0,3,5,6},Mod[#,7]]&] (* Vincenzo Librandi, Aug 12 2012 *)
Showing 1-3 of 3 results.