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 10 results.

A289292 Coefficients in expansion of E_4^(1/2).

Original entry on oeis.org

1, 120, -6120, 737760, -107249640, 17385063120, -3014720249760, 547287510713280, -102701836021530600, 19762301660609250840, -3878226140959368843120, 773209219953012480001440, -156173318001506652330786720, 31888935085481430265623676560
Offset: 0

Views

Author

Seiichi Manyama, Jul 02 2017

Keywords

Links

Crossrefs

E_k^(1/2): A289291 (k=2), this sequence (k=4), A289293 (k=6), A004009 (k=8), A289294 (k=10), A289295 (k=14).
E_4^(k/8): A108091 (k=1), A289307 (k=2), A289308 (k=3), this sequence (k=4), A289309 (k=5), A289318 (k=6), A289319 (k=7).
Cf. A001421, A004009 (E_4), A110163.

Programs

  • Mathematica
    terms = 14;
E4[x_] = 1 + 240*Sum[k^3*x^k/(1 - x^k), {k, 1, terms}];
E4[x]^(1/2) + O[x]^terms // CoefficientList[#, x]& (* Jean-François Alcover, Feb 23 2018 *)

Formula

G.f.: Product_{n>=1} (1-q^n)^(A110163(n)/2).
a(n) ~ (-1)^(n+1) * c * exp(Pi*sqrt(3)*n) / n^(3/2), where c = 3*Gamma(1/3)^9 / (32*sqrt(2)*Pi^(13/2)) = 0.27646925986847687648926173728588572192308632719... - Vaclav Kotesovec, Jul 02 2017, updated Mar 05 2018
G.f.: 3F2(1/6, 1/2, 5/6; 1, 1; 1728/j) where j is the elliptic modular invariant (A000521). - Seiichi Manyama, Jul 07 2017

A289293 Coefficients in expansion of E_6^(1/2).

Original entry on oeis.org

1, -252, -40068, -10158624, -3362961924, -1254502939032, -502480721822688, -211053631376919744, -91717692784641665028, -40892713821496126310364, -18600635229558474625901928, -8597703758971125751979122656
Offset: 0

Views

Author

Seiichi Manyama, Jul 02 2017

Keywords

Links

Crossrefs

E_k^(1/2): A289291 (k=2), A289292 (k=4), this sequence (k=6), A004009 (k=8), A289294 (k=10), A289295 (k=14).
Cf. A013973 (E_6), A288851.

Programs

  • Mathematica
    terms = 12;
E6[x_] = 1 - 504*Sum[k^5*x^k/(1 - x^k), {k, 1, terms}];
E6[x]^(1/2) + O[x]^terms // CoefficientList[#, x]& (* Jean-François Alcover, Feb 23 2018 *)

Formula

G.f.: Product_{n>=1} (1-q^n)^(A288851(n)/2).
a(n) ~ c * exp(2*Pi*n) / n^(3/2), where c = -3*sqrt(2)*Pi^(3/2) / (16*Gamma(3/4)^8) = -0.2903826839827320330247215149377503818798115... - Vaclav Kotesovec, Jul 02 2017, updated Mar 05 2018

A289392 Coefficients in expansion of E_2^(1/4).

Original entry on oeis.org

1, -6, -72, -1104, -20238, -405792, -8601840, -189317568, -4281478272, -98841343686, -2318973049008, -55118876238000, -1324194430710912, -32099173821105312, -784045854628721568, -19276683937074656064, -476644852188898489662
Offset: 0

Views

Author

Seiichi Manyama, Jul 05 2017

Keywords

Links

Crossrefs

E_2^(k/4): this sequence (k=1), A289291 (k=2), A289393 (k=3).
E_k^(1/4): this sequence (k=2), A289307 (k=4), A289326 (k=6), A289292 (k=8), A110150 (k=10), A289391 (k=14).
Cf. A004984, A006352 (E_2), A108091, A109817, A289394.

Programs

  • Mathematica
    nmax = 20; CoefficientList[Series[(1 - 24*Sum[DivisorSigma[1, k]*x^k, {k, 1, nmax}])^(1/4), {x, 0, nmax}], x] (* Vaclav Kotesovec, Jul 08 2017 *)

Formula

G.f.: Product_{n>=1} (1-q^n)^A289394(n).
a(n) ~ c / (n^(5/4) * r^n), where r = A211342 = 0.03727681029645165815098078565... is the root of the equation Sum_{k>=1} A000203(k) * r^k = 1/24 and c = -0.209452682241344640265132676904094736935029272937832600102950644347... - Vaclav Kotesovec, Jul 08 2017
G.f.: Sum_{k>=0} A004984(k) * (3*f(q))^k where f(q) is Sum_{k>=1} sigma_1(k)*q^k. - Seiichi Manyama, Jun 16 2018

A289294 Coefficients in expansion of E_10^(1/2).

Original entry on oeis.org

1, -132, -76428, -12686784, -4629945804, -1581036186312, -643032851554368, -264454897726360704, -114830224962140965068, -50847479367845783084484, -23070238839261012248537688, -10629338992044523324726971456
Offset: 0

Views

Author

Seiichi Manyama, Jul 02 2017

Keywords

Links

Crossrefs

E_k^(1/2): A289291 (k=2), A289292 (k=4), A289293 (k=6), A004009 (k=8), this sequence (k=10), A289295 (k=14).
Cf. A013974 (E_10), A289024.

Programs

  • Mathematica
    nmax = 20; s = 10; CoefficientList[Series[Sqrt[1 - 2*s/BernoulliB[s] * Sum[DivisorSigma[s - 1, k]*x^k, {k, 1, nmax}]], {x, 0, nmax}], x] (* Vaclav Kotesovec, Jul 02 2017 *)

Formula

G.f.: Product_{n>=1} (1-q^n)^(A289024(n)/2).
a(n) ~ c * exp(2*Pi*n) / n^(3/2), where c = -3^(3/2) * Pi^(5/2) / (2^(9/2) * Gamma(3/4)^12) = -0.3503612261281732359954402284478780636268623476628... - Vaclav Kotesovec, Jul 02 2017, updated Mar 05 2018

A289565 Coefficients in expansion of 1/E_2^(1/2).

Original entry on oeis.org

1, 12, 252, 5664, 133356, 3224952, 79387488, 1978996416, 49797787788, 1262193008556, 32177428972632, 824182154521056, 21193138994244960, 546767126418119352, 14146104826919725632, 366887630982365262144, 9535791498480146879436
Offset: 0

Views

Author

Seiichi Manyama, Jul 08 2017

Keywords

Links

Crossrefs

1/E_k^(1/2): this sequence (k=2), A289566 (k=4), A289567 (k=6), A001943 (k=8), A289568 (k=10), A289569 (k=14).
Cf. A288816 (1/E_2), A288968, A289291 (E_2^(1/2)).

Programs

  • Mathematica
    nmax = 20; CoefficientList[Series[(1 - 24*Sum[DivisorSigma[1, k]*x^k, {k, 1, nmax}])^(-1/2), {x, 0, nmax}], x] (* Vaclav Kotesovec, Jul 09 2017 *)

Formula

G.f.: Product_{n>=1} (1-q^n)^(-A288968(n)/2).
a(n) ~ c / (sqrt(n) * r^n), where r = A211342 = 0.03727681029645165815098078565... is the root of the equation Sum_{k>=1} A000203(k) * r^k = 1/24 and c = 0.535261044779387956394739769118415667289349331646288208543596374426... - Vaclav Kotesovec, Jul 09 2017

A289295 Coefficients in expansion of E_14^(1/2).

Original entry on oeis.org

1, -12, -98388, -20312544, -5889254484, -2083830070392, -810894400450848, -334381509272710464, -143464412162723380308, -63364234685240118242604, -28614423885137875351570248, -13150804531745894256074689056
Offset: 0

Views

Author

Seiichi Manyama, Jul 02 2017

Keywords

Links

Crossrefs

E_k^(1/2): A289291 (k=2), A289292 (k=4), A289293 (k=6), A004009 (k=8), A289294 (k=10), this sequence (k=14).
Cf. A058550 (E_14), A289029.

Programs

  • Mathematica
    nmax = 20; s = 14; CoefficientList[Series[Sqrt[1 - 2*s/BernoulliB[s] * Sum[DivisorSigma[s - 1, k]*x^k, {k, 1, nmax}]], {x, 0, nmax}], x] (* Vaclav Kotesovec, Jul 02 2017 *)

Formula

G.f.: Product_{n>=1} (1-q^n)^(A289029(n)/2).
a(n) ~ c * exp(2*Pi*n) / n^(3/2), where c = -9 * Pi^(7/2) / (2^(11/2) * Gamma(3/4)^16) = -0.422728335899452596724927626919867458580193404969719... - Vaclav Kotesovec, Jul 02 2017, updated Mar 05 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

Cf. A004009 (E_4), A006352 (E_2), A108091, A289247, A289291, A294626, A294976.

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

A289393 Coefficients in expansion of E_2^(3/4).

Original entry on oeis.org

1, -18, -108, -936, -13194, -224424, -4218264, -84318336, -1759467636, -37903487130, -836893437912, -18844318997496, -431163494289720, -9997357777073064, -234430475682110256, -5550426839122171776, -132513976699508759994
Offset: 0

Views

Author

Seiichi Manyama, Jul 05 2017

Keywords

Links

Crossrefs

E_2^(k/4): A289392 (k=1), A289291 (k=2), this sequence (k=3).
Cf. A006352 (E_2), A289394.

Programs

  • Mathematica
    nmax = 20; CoefficientList[Series[(1 - 24*Sum[DivisorSigma[1, k]*x^k, {k, 1, nmax}])^(3/4), {x, 0, nmax}], x] (* Vaclav Kotesovec, Jul 08 2017 *)

Formula

G.f.: Product_{n>=1} (1-q^n)^(3*A289394(n)).
a(n) ~ c / (n^(7/4) * r^n), where r = A211342 = 0.03727681029645165815098078565... is the root of the equation Sum_{k>=1} A000203(k) * r^k = 1/24 and c = -0.22385630328806525639758543854251232523806175231599584032442913209... - Vaclav Kotesovec, Jul 08 2017

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

Cf. A289291, A289540, A294975, A294976.

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

A289344 Coefficients in expansion of E_2^(1/2)/Product_{k>=1} (1-q^k).

Original entry on oeis.org

1, -11, -118, -1473, -23635, -434861, -8659573, -181387821, -3936961298, -87743843970, -1996149058302, -46163368994680, -1082012001849499, -25646334881233711, -613664275728573585, -14803437882920457712, -359626550280367615329
Offset: 0

Views

Author

Seiichi Manyama, Jul 03 2017

Keywords

Crossrefs

Cf. A006352 (E_2), A288995, A289062, A289291.
Cf. A106205, A106203.

Programs

  • Mathematica
    nmax = 20; CoefficientList[Series[Sqrt[1 - 24*Sum[DivisorSigma[1, k]*x^k, {k, 1, nmax}]] / Product[1 - x^k, {k, 1, nmax}], {x, 0, nmax}], x] (* Vaclav Kotesovec, Jul 03 2017 *)

Formula

G.f.: Product_{k>=1} (1-q^k)^(A288995(k)/24).
a(n) ~ c / (n^(3/2) * r^n), where r = A211342 = 0.03727681029645165815098078565... is the root of the equation Sum_{k>=1} A000203(k) * r^k = 1/24 and c = -0.309300289625571303778321676728514880378401177270067457514896529... - Vaclav Kotesovec, Jul 03 2017
Showing 1-10 of 10 results.

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