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 1-6 of 6 results.

A289368 Coefficients in expansion of (E_6^2/E_4^3)^(1/24).

Original entry on oeis.org

1, -72, -6048, -4217184, -1264437504, -606533479920, -251777443450752, -117085712395216320, -53634689421870422016, -25408429618361083967592, -12110787335129301116994240, -5854620911089647830793873696
Offset: 0

Views

Author

Seiichi Manyama, Jul 04 2017

Keywords

Crossrefs

(E_6^2/E_4^3)^(k/288): A289366 (k=1), A296609 (k=2), A296614 (k=3), A296652 (k=4), A297021 (k=6), A299422 (k=8), A299862 (k=9), this sequence (k=12), A299856 (k=16), A299857 (k=18), A299858 (k=24), A299863 (k=32), A299859 (k=36), A299860 (k=48), A299861 (k=72), A299414 (k=96), A299413 (k=144), A289210 (k=288).
Cf. A000521 (j), A108091 (E_4^(1/8)), A109817 (E_6^(1/12)).

Programs

  • Mathematica
    nmax = 20; CoefficientList[Series[((1 - 504*Sum[DivisorSigma[5,k]*x^k, {k, 1, nmax}])^2 / (1 + 240*Sum[DivisorSigma[3,k]*x^k, {k, 1, nmax}])^3)^(1/24), {x, 0, nmax}], x] (* Vaclav Kotesovec, Jul 08 2017 *)

Formula

G.f.: (1 - 1728/j)^(1/24).
G.f.: Product_{n>=1} (1-q^n)^(12*A289367(n)).
a(n) ~ c * exp(2*Pi*n) / n^(13/12), where c = -Gamma(1/4)^(1/3) / (2^(7/3) * 3^(23/24) * Pi^(1/4) * Gamma(11/12)) = -0.07569217204117312767729284017524325060022536591050774997610261275428... - Vaclav Kotesovec, Jul 08 2017, updated Mar 04 2018
a(n) * A289369(n) ~ -(sqrt(3)-1) * exp(4*Pi*n) / (24*sqrt(2)*Pi*n^2). - Vaclav Kotesovec, Mar 04 2018

A294974 Coefficients in expansion of (E_2^4/E_4)^(1/8).

Original entry on oeis.org

1, -42, 4032, -659904, 118064226, -22406634432, 4407587356032, -888750999070464, 182478248639753472, -37986867560948245674, 7994272624037726124672, -1697243410477799687716416, 362963150140702802158191360, -78095916585903527021840348352
Offset: 0

Views

Author

Seiichi Manyama, Feb 12 2018

Keywords

Comments

Also coefficients in expansion of (E_2^8/E_8)^(1/16).

Crossrefs

Programs

  • Mathematica
    terms = 14;
    E2[x_] = 1 - 24*Sum[k*x^k/(1 - x^k), {k, 1, terms}];
    E4[x_] = 1 + 240*Sum[k^3*x^k/(1 - x^k), {k, 1, terms}];
    (E2[x]^4/E4[x])^(1/8) + O[x]^terms // CoefficientList[#, x]& (* Jean-François Alcover, Feb 26 2018 *)

Formula

G.f.: Product_{n>=1} (1-q^n)^A294626(n).
a(n) ~ (-1)^n * 2^(13/8) * Pi * exp(Pi*sqrt(3)*n) / (Gamma(1/8) * Gamma(1/3)^(9/4) * n^(7/8)). - Vaclav Kotesovec, Jun 03 2018

A294975 a(n) = (1/(24*n)) * Sum_{d|n} A008683(n/d) * (A288840(d) - A288877(d)).

Original entry on oeis.org

30, 11775, 4261790, 1712983575, 733856931102, 327479190724415, 150310619778297630, 70428822637214055855, 33523597190372498303390, 16156445902947621421555071, 7865129058155113639991368350, 3860735065245244345161225213335
Offset: 1

Views

Author

Seiichi Manyama, Feb 12 2018

Keywords

Crossrefs

Programs

  • Mathematica
    terms = 12;
    E2[x_] = 1 - 24*Sum[k*x^k/(1 - x^k), {k, 1, terms}];
    E4[x_] = 1 + 240*Sum[k^3*x^k/(1 - x^k), {k, 1, terms}];
    E6[x_] = 1 - 504*Sum[k^5*x^k/(1 - x^k), {k, 1, terms}];
    E8[x_] = 1 + 480*Sum[k^7*x^k/(1 - x^k), {k, 1, terms}];
    a[n_] := (1/(24 n))*Sum[MoebiusMu[n/d]*SeriesCoefficient[E8[x]/E6[x] - E4[x]/E2[x], {x, 0, d}], {d, Divisors[n]}];
    Array[a, terms] (* Jean-François Alcover, Feb 26 2018 *)

Formula

a(n) ~ exp(2*Pi*n) / (12*n). - Vaclav Kotesovec, Jun 03 2018

A295788 Coefficients in expansion of (E_10/E_2^10)^(1/4).

Original entry on oeis.org

1, -6, -41652, -11504904, -4378103178, -1652544433080, -700184843900712, -302796005909941632, -136251754253507319300, -62421509259448987324542, -29147951871527035454309160, -13787807362002100397282325912
Offset: 0

Views

Author

Seiichi Manyama, Feb 13 2018

Keywords

Crossrefs

Programs

  • Mathematica
    terms = 12;
    E2[x_] = 1 - 24*Sum[k*x^k/(1 - x^k), {k, 1, terms}];
    E10[x_] = 1 - 264*Sum[k^9*x^k/(1 - x^k), {k, 1, terms}];
    (E10[x]/E2[x]^10)^(1/4) + O[x]^terms // CoefficientList[#, x]& (* Jean-François Alcover, Feb 26 2018 *)

Formula

a(n) ~ -Pi^4 * exp(2*Pi*n) / (3^(7/4) * 2^(15/4) * Gamma(3/4)^7 * n^(5/4)). - Vaclav Kotesovec, Jun 03 2018

A299712 Coefficients in expansion of (E_14/E_2^14)^(1/4).

Original entry on oeis.org

1, 78, -44928, -14386944, -5323508814, -1996794824544, -833028042023424, -358702721913389568, -160514702770156497360, -73334654476723097306706, -34151846554093744054455552, -16125009656471947012310740224
Offset: 0

Views

Author

Seiichi Manyama, Feb 17 2018

Keywords

Crossrefs

Programs

  • Mathematica
    terms = 12;
    E2[x_] = 1 - 24*Sum[k*x^k/(1 - x^k), {k, 1, terms}];
    E4[x_] = 1 + 240*Sum[k^3*x^k/(1 - x^k), {k, 1, terms}];
    E10[x_] = 1 - 264*Sum[k^9*x^k/(1 - x^k), {k, 1, terms}];
    E14[x_] = E4[x]*E10[x];
    (E14[x]/E2[x]^14)^(1/4) + O[x]^terms // CoefficientList[#, x]& (* Jean-François Alcover, Feb 26 2018 *)

Formula

a(n) ~ -2^(3/4) * sqrt(3) * Pi^(11/2) * exp(2*Pi*n) / (864 * Gamma(3/4)^9 * n^(5/4)). - Vaclav Kotesovec, Jun 03 2018

A294979 Coefficients in expansion of (E_2^6/E_6)^(1/12).

Original entry on oeis.org

1, 30, 12240, 4620000, 1915684770, 839549366208, 381374756189280, 177631327935911040, 84272487587664762240, 40549569894460426101150, 19730577674798681251391712, 9687875889040210133058857760, 4792614349874614536514510456320
Offset: 0

Views

Author

Seiichi Manyama, Feb 12 2018

Keywords

Crossrefs

Programs

  • Mathematica
    terms = 13;
    E2[x_] = 1 - 24*Sum[k*x^k/(1 - x^k), {k, 1, terms}];
    E6[x_] = 1 - 504*Sum[k^5*x^k/(1 - x^k), {k, 1, terms}];
    (E2[x]^6/E6[x])^(1/12) + O[x]^terms // CoefficientList[#, x]& (* Jean-François Alcover, Feb 26 2018 *)

Formula

Convolution inverse of A294976.
G.f.: Product_{n>=1} (1-q^n)^(-A294975(n)).
a(n) ~ 2^(13/12) * 3^(1/3) * sqrt(Pi) * exp(2*Pi*n) / (Gamma(1/12) * Gamma(1/4)^(4/3) * n^(11/12)). - Vaclav Kotesovec, Jun 03 2018
Showing 1-6 of 6 results.