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 1-10 of 19 results. Next

A320124 Number of integer solutions to a^2 + b^2 + 2*c^2 + 3*d^2 = n.

Original entry on oeis.org

1, 4, 6, 10, 20, 20, 24, 40, 22, 28, 56, 20, 50, 80, 28, 80, 84, 32, 78, 80, 68, 100, 120, 80, 88, 124, 56, 82, 136, 100, 140, 200, 86, 80, 192, 72, 140, 240, 120, 200, 248, 80, 112, 176, 100, 260, 224, 160, 210, 172, 186, 128, 272, 180, 240, 400, 124, 200, 280, 116
Offset: 0

Views

Author

Seiichi Manyama, Oct 06 2018

Keywords

Comments

a(n) > 0 for n >= 0.

Crossrefs

Formula

G.f.: theta_3(q)^2 * theta_3(q^2) * theta_3(q^3).

A320125 Number of integer solutions to a^2 + b^2 + 2*c^2 + 4*d^2 = n.

Original entry on oeis.org

1, 4, 6, 8, 14, 16, 20, 32, 30, 28, 40, 40, 36, 48, 48, 32, 62, 72, 42, 72, 72, 64, 100, 96, 68, 84, 120, 80, 112, 112, 48, 128, 126, 80, 108, 128, 98, 144, 180, 96, 136, 168, 160, 168, 180, 112, 144, 192, 132, 228, 126, 144, 216, 208, 200, 160, 240, 144, 280, 232
Offset: 0

Views

Author

Seiichi Manyama, Oct 06 2018

Keywords

Comments

a(n) > 0 for n >= 0.

Crossrefs

Formula

G.f.: theta_3(q)^2 * theta_3(q^2) * theta_3(q^4).

A320126 Number of integer solutions to a^2 + b^2 + 2*c^2 + 5*d^2 = n.

Original entry on oeis.org

1, 4, 6, 8, 12, 10, 16, 28, 22, 36, 40, 24, 56, 36, 24, 64, 28, 64, 78, 24, 58, 48, 68, 92, 80, 92, 72, 112, 92, 48, 104, 96, 118, 176, 64, 48, 124, 84, 148, 160, 104, 120, 176, 120, 72, 146, 88, 204, 216, 124, 126, 96, 180, 148, 224, 188, 120, 304, 216, 120, 224, 96
Offset: 0

Views

Author

Seiichi Manyama, Oct 06 2018

Keywords

Comments

a(n) > 0 for n >= 0.

Crossrefs

Formula

G.f.: theta_3(q)^2 * theta_3(q^2) * theta_3(q^5).

A320127 Number of integer solutions to a^2 + b^2 + 2*c^2 + 6*d^2 = n.

Original entry on oeis.org

1, 4, 6, 8, 12, 8, 10, 24, 18, 28, 48, 24, 40, 56, 12, 40, 60, 32, 78, 72, 24, 48, 48, 48, 70, 84, 84, 80, 120, 56, 32, 120, 66, 120, 192, 48, 84, 152, 36, 112, 144, 80, 180, 168, 120, 104, 96, 96, 136, 172, 126, 160, 168, 104, 82, 192, 84, 144, 336, 120, 200, 248, 60, 168
Offset: 0

Views

Author

Seiichi Manyama, Oct 06 2018

Keywords

Comments

a(n) > 0 for n >= 0.

Crossrefs

Formula

G.f.: theta_3(q)^2 * theta_3(q^2) * theta_3(q^6).

A320128 Number of integer solutions to a^2 + b^2 + 2*c^2 + 7*d^2 = n.

Original entry on oeis.org

1, 4, 6, 8, 12, 8, 8, 18, 14, 24, 40, 32, 40, 40, 32, 28, 36, 64, 46, 72, 72, 16, 56, 40, 40, 88, 72, 80, 82, 64, 44, 64, 86, 96, 128, 144, 64, 64, 136, 44, 136, 160, 80, 144, 128, 120, 92, 128, 104, 164, 158, 96, 168, 80, 144, 160, 168, 108, 104, 232, 108, 168, 192, 82
Offset: 0

Views

Author

Seiichi Manyama, Oct 06 2018

Keywords

Comments

a(n) > 0 for n >= 0.

Crossrefs

Formula

G.f.: theta_3(q)^2 * theta_3(q^2) * theta_3(q^7).

A236923 Number of integer solutions to a^2 + b^2 + c^2 + 4*d^2 = n.

Original entry on oeis.org

1, 6, 12, 8, 8, 36, 48, 16, 24, 78, 72, 24, 32, 84, 96, 48, 24, 108, 156, 40, 48, 192, 144, 48, 96, 186, 168, 80, 64, 180, 288, 64, 24, 288, 216, 96, 104, 228, 240, 112, 144, 252, 384, 88, 96, 468, 288, 96, 96, 342, 372, 144, 112, 324, 480, 144, 192, 480, 360, 120, 192, 372, 384, 208, 24, 504, 576, 136, 144, 576, 576, 144, 312, 444, 456, 248, 160, 576, 672
Offset: 0

Views

Author

N. J. A. Sloane, Feb 14 2014

Keywords

Crossrefs

For number of solutions to a^2+b^2+c^2+k*d^2=n for k=1,2,3,4,5,6,7,8,12 see A000118, A236928, A236926, A236923, A236930, A236931, A236932, A236927, A236933.

Programs

  • Maple
    with(numtheory);
    s:=n-> if whattype(n) = integer then sigma(n) else 0; fi;
    f:=proc(n) global s;
      if (n mod 4) = 0 then 8*s(n/4)-32*s(n/16)
    elif (n mod 4) = 2 then 12*s(n/2)
    elif (n mod 4) = 3 then 2*s(n)
    else 6*s(n);
    fi; end;
    [seq(f(n),n=1..100)];
    # a(0)=1 must be added separately
  • Mathematica
    EllipticTheta[3, 0, q]^3*EllipticTheta[3, 0, q^4] + O[q]^80 // CoefficientList[#, q]& (* Jean-François Alcover, Mar 04 2023, after Ilya Gutkovskiy *)

Formula

See Maple code.
G.f.: theta_3(q)^3*theta_3(q^4), where theta_3() is the Jacobi theta function. - Ilya Gutkovskiy, Aug 01 2018

A320130 Number of integer solutions to a^2 + b^2 + 2*c^2 + 8*d^2 = n.

Original entry on oeis.org

1, 4, 6, 8, 12, 8, 8, 16, 8, 20, 36, 24, 48, 40, 16, 48, 24, 40, 78, 40, 72, 64, 24, 48, 32, 60, 84, 80, 96, 40, 48, 64, 24, 96, 108, 96, 156, 72, 40, 112, 48, 104, 192, 88, 144, 168, 48, 96, 96, 100, 186, 144, 168, 136, 80, 144, 64, 160, 180, 120, 288, 104, 64, 208
Offset: 0

Views

Author

Seiichi Manyama, Oct 06 2018

Keywords

Comments

a(n) > 0 for n >= 0.

Crossrefs

Formula

G.f.: theta_3(q)^2 * theta_3(q^2) * theta_3(q^8).

A320131 Number of integer solutions to a^2 + b^2 + 2*c^2 + 9*d^2 = n.

Original entry on oeis.org

1, 4, 6, 8, 12, 8, 8, 16, 6, 14, 32, 20, 40, 48, 16, 32, 44, 28, 54, 72, 40, 64, 72, 16, 40, 52, 56, 92, 96, 56, 32, 80, 38, 48, 104, 64, 102, 144, 52, 32, 112, 44, 128, 168, 68, 136, 128, 96, 104, 132, 62, 144, 176, 104, 172, 96, 112, 112, 192, 116, 96, 240, 96, 176
Offset: 0

Views

Author

Seiichi Manyama, Oct 06 2018

Keywords

Comments

a(n) > 0 for n >= 0.

Crossrefs

Formula

G.f.: theta_3(q)^2 * theta_3(q^2) * theta_3(q^9).

A320132 Number of integer solutions to a^2 + b^2 + 2*c^2 + 10*d^2 = n.

Original entry on oeis.org

1, 4, 6, 8, 12, 8, 8, 16, 6, 12, 26, 16, 36, 40, 24, 32, 28, 48, 42, 48, 72, 32, 72, 64, 8, 60, 48, 64, 108, 56, 48, 64, 54, 64, 64, 72, 84, 104, 120, 32, 26, 88, 72, 120, 144, 88, 88, 144, 84, 92, 126, 64, 216, 152, 80, 160, 24, 128, 180, 144, 156, 104, 192, 128, 92
Offset: 0

Views

Author

Seiichi Manyama, Oct 06 2018

Keywords

Comments

a(n) > 0 for n >= 0.

Crossrefs

Formula

G.f.: theta_3(q)^2 * theta_3(q^2) * theta_3(q^10).

A320133 Number of integer solutions to a^2 + b^2 + 2*c^2 + 11*d^2 = n.

Original entry on oeis.org

1, 4, 6, 8, 12, 8, 8, 16, 6, 12, 24, 10, 32, 36, 16, 40, 28, 32, 62, 36, 48, 64, 40, 64, 56, 28, 56, 56, 80, 68, 48, 80, 38, 80, 80, 32, 92, 88, 88, 112, 40, 16, 112, 52, 90, 144, 44, 120, 128, 100, 78, 96, 116, 144, 160, 112, 128, 80, 136, 104, 144, 132, 92, 240
Offset: 0

Views

Author

Seiichi Manyama, Oct 06 2018

Keywords

Comments

a(n) > 0 for n >= 0.

Crossrefs

Formula

G.f.: theta_3(q)^2 * theta_3(q^2) * theta_3(q^11).
Showing 1-10 of 19 results. Next