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.

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A145154 Coefficients in expansion of Eisenstein series E_1.

Original entry on oeis.org

1, 4, 8, 8, 12, 8, 16, 8, 16, 12, 16, 8, 24, 8, 16, 16, 20, 8, 24, 8, 24, 16, 16, 8, 32, 12, 16, 16, 24, 8, 32, 8, 24, 16, 16, 16, 36, 8, 16, 16, 32, 8, 32, 8, 24, 24, 16, 8, 40, 12, 24, 16, 24, 8, 32, 16, 32, 16, 16, 8, 48
Offset: 0

Views

Author

N. J. A. Sloane, Feb 28 2009

Keywords

Examples

			1 + 4*q + 8*q^2 + 8*q^3 + 12*q^4 + 8*q^5 + 16*q^6 + 8*q^7 + 16*q^8 + ...
		

Crossrefs

Cf. A000005, A006352 (E_2), A004009 (E_4), A013973 (E_6), A008410 (E_8), A013974 (E_10), A029828 (E_12), A058550 (E_14), A029829 (E_16), A029830 (E_20), A029831 (E_24).

Programs

  • Maple
    with(numtheory); E:=proc(k) series(1-(2*k/bernoulli(k))*add( sigma[k-1](n)*q^n, n=1..60),q,61); end; E(1);
  • Mathematica
    terms = 61; CoefficientList[1+4*Sum[x^k/(1-x^k), {k, 1, terms}]+O[x]^terms, x] (* Jean-François Alcover, Feb 27 2018 *)
  • PARI
    {a(n) = if( n<1, n==0, 4 * numdiv(n))} /* Michael Somos, Jul 04 2011 */

Formula

a(0) = 1; for n >= 1, a(n) = 4*A000005(n). [After the PARI-program of Michael Somos.] - Antti Karttunen, May 25 2017

A282357 Coefficients in q-expansion of E_4^2*E_6^3, where E_4 and E_6 are respectively the Eisenstein series A004009 and A013973.

Original entry on oeis.org

1, -1032, 48312, 171162336, -6444771144, -10105554483504, -1037089473751584, -48959817978105408, -1378102838778701640, -26186640301645703016, -364779940958775418032, -3952291567255306906464, -34798629548716507265568, -257403564989318828310384
Offset: 0

Views

Author

Seiichi Manyama, Feb 13 2017

Keywords

Crossrefs

Cf. A008410 (E_4^2 = E_8), A058550 (E_4^2*E_6 = E_14), A282292 (E_4^2*E_6^2 = E_10^2), this sequence (E_4^2*E_6^3).

Programs

  • Mathematica
    terms = 14;
    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}];
    E4[x]^2*E6[x]^3 + O[x]^terms // CoefficientList[#, x]& (* Jean-François Alcover, Feb 27 2018 *)

A282401 Eisenstein series E_28(q) (alternate convention E_14(q)), multiplied by 3392780147.

Original entry on oeis.org

3392780147, 6960, 934155393840, 53074158495516480, 125380214560150002480, 51856040954589843756960, 7123493021854278627673920, 457358042050198589771226240, 16828247534415852672059972400, 404722169541211889603611092720
Offset: 0

Views

Author

Seiichi Manyama, Feb 14 2017

Keywords

Crossrefs

Cf. A006352 (E_2), A004009 (E_4), A013973 (E_6), A008410 (E_8), A013974 (E_10), A029828 (691*E_12), A058550 (E_14), A029829 (3617*E_16), A279892 (43867*E_18), A029830 (174611*E_20), A279893 (77683*E_22), A029831 (236364091*E_24), A282356 (657931*E_26), this sequence (3392780147*E_28).
Cf. A282402 (E_4^7), A282403 (E_4^4*E_6^2), A282404 (E_4*E_6^4).

Programs

  • Mathematica
    terms = 10;
    E28[x_] = 3392780147 + 6960*Sum[k^27*x^k/(1 - x^k), {k, 1, terms}];
    E28[x] + O[x]^terms // CoefficientList[#, x]& (* Jean-François Alcover, Feb 26 2018 *)

Formula

a(n) = 489693897*A282402(n) + 2507636250*A282403(n) + 395450000*A282404(n).

A282402 Coefficients in q-expansion of E_4^7, where E_4 is the Eisenstein series A004009.

Original entry on oeis.org

1, 1680, 1224720, 505659840, 129351117840, 21060890131680, 2160822606183360, 134717272385473920, 4957295423282269200, 119288258695393463760, 2051465861242156554720, 26894077218337493424960, 281803532524538902825920
Offset: 0

Views

Author

Seiichi Manyama, Feb 14 2017

Keywords

Crossrefs

Cf. A004009 (E_4), A008410 (E_4^2), A008411 (E_4^3), A282012 (E_4^4), A282015 (E_4^5), A282330 (E_4^6), this sequence (E_4^7).

Programs

  • Mathematica
    terms = 13;
    E4[x_] = 1 + 240*Sum[k^3*x^k/(1 - x^k), {k, 1, terms}];
    E4[x]^7 + O[x]^terms // CoefficientList[#, x]& (* Jean-François Alcover, Feb 27 2018 *)

A290009 Coefficients in expansion of 691*E_4*E_8*E_12.

Original entry on oeis.org

691, 563040, 305307360, 131729109120, 34085393629920, 4587384326495040, 302027782271806080, 10484303481804821760, 226150164335242994400, 3395290157453914541280, 38308806132696980919360, 343030311387007824977280, 2537869275676057371269760
Offset: 0

Views

Author

Seiichi Manyama, Jul 17 2017

Keywords

Crossrefs

Cf. A004009 (E_4), A008410 (E_8), A008411 (E_4^3), A029828 (691*E_12).
Cf. A290010.

Programs

  • Mathematica
    terms = 13;
    E4[x_] = 1 + 240*Sum[k^3*x^k/(1 - x^k), {k, 1, terms}];
    E12[x_] = 1 + (65520/691)*Sum[k^11*x^k/(1 - x^k), {k, 1, terms}];
    691*E4[x]^3*E12[x] + O[x]^terms // CoefficientList[#, x]& (* Jean-François Alcover, Feb 26 2018 *)

Formula

G.f.: 691*E_4^3*E_12.

A294183 Coefficients in expansion of E_6/E_8.

Original entry on oeis.org

1, -984, 393768, -129252576, 38684099112, -10970838627984, 3003345011096352, -801909012374388672, 210169391033048138280, -54295810529811041175672, 13867098270790394508774768, -3508693915623201191415922848
Offset: 0

Views

Author

Seiichi Manyama, Feb 11 2018

Keywords

Crossrefs

Cf. A008410 (E_8). A013973 (E_6), A287933, A288840.
E_k/E_{k+2}: A294181 (k=2), A294182 (k=4), this sequence (k=6).

Programs

  • Mathematica
    terms = 12;
    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}];
    E6[x]/E8[x] + O[x]^terms // CoefficientList[#, x]& (* Jean-François Alcover, Feb 23 2018 *)

Formula

Convolution inverse of A288840.
a(n) ~ (-1)^n * 512 * Pi^12 * exp(Pi*sqrt(3)*n) * n / (3 * Gamma(1/3)^18). - Vaclav Kotesovec, Jun 03 2018

A083728 a(0) = 1, a(n) = 480*sigma(n).

Original entry on oeis.org

1, 480, 1440, 1920, 3360, 2880, 5760, 3840, 7200, 6240, 8640, 5760, 13440, 6720, 11520, 11520, 14880, 8640, 18720, 9600, 20160, 15360, 17280, 11520, 28800, 14880, 20160, 19200, 26880, 14400, 34560, 15360, 30240, 23040, 25920, 23040, 43680, 18240, 28800
Offset: 0

Views

Author

N. J. A. Sloane, Jun 16 2003

Keywords

Crossrefs

Programs

A282182 Eisenstein series E_30(q) (alternate convention E_15(q)), multiplied by 1723168255201.

Original entry on oeis.org

1723168255201, -171864, -92268782591832, -11795091175438423776, -49536425459206569762648, -32012164592742919922046864, -6332441368275869747902027488, -553385882817076320573218661312, -26594665913504249904864455466840
Offset: 0

Views

Author

Seiichi Manyama, Feb 16 2017

Keywords

Crossrefs

Cf. A006352 (E_2), A004009 (E_4), A013973 (E_6), A008410 (E_8), A013974 (E_10), A029828 (691*E_12), A058550 (E_14), A029829 (3617*E_16), A279892 (43867*E_18), A029830 (174611*E_20), A279893 (77683*E_22), A029831 (236364091*E_24), A282356 (657931*E_26), A282401 (3392780147*E_28), this sequence (1723168255201*E_30).
Cf. A282382 (E_4^6*E_6), A282461 (E_4^3*E_6^3), A282433 (E_6^5).

Programs

  • Mathematica
    terms = 9;
    E30[x_] = 1723168255201 - 171864*Sum[k^29*x^k/(1 - x^k), {k, 1, terms}];
    E30[x] + O[x]^terms // CoefficientList[#, x]& (* Jean-François Alcover, Feb 26 2018 *)

Formula

a(n) = 815806500201*A282382(n) + 881340705000*A282461(n) + 26021050000*A282433(n).

A282474 Coefficients in q-expansion of E_4^8, where E_4 is the Eisenstein series A004009.

Original entry on oeis.org

1, 1920, 1630080, 803228160, 253366181760, 53205643249920, 7498254194403840, 699684356363412480, 42100628403784982400, 1614922125605880493440, 42332208491309728078080, 812648422343847344279040, 12060223533365891970132480
Offset: 0

Views

Author

Seiichi Manyama, Feb 16 2017

Keywords

Crossrefs

Cf. A004009 (E_4), A008410 (E_4^2), A008411 (E_4^3), A282012 (E_4^4), A282015 (E_4^5), A282330 (E_4^6), A282402 (E_4^7), this sequence (E_4^8).

Programs

  • Mathematica
    terms = 13;
    E4[x_] = 1 + 240*Sum[k^3*x^k/(1 - x^k), {k, 1, terms}];
    E4[x]^8 + O[x]^terms // CoefficientList[#, x]& (* Jean-François Alcover, Feb 27 2018 *)

A282543 Coefficients in q-expansion of E_4^2*E_6^4, where E_4 and E_6 are respectively the Eisenstein series A004009 and A013973.

Original entry on oeis.org

1, -1536, 551808, 163854336, -93387735168, -9709554816000, 4142226444876288, 642510156233453568, 41792421673548259200, 1615606968766288470528, 42343208407470359036160, 812663841518551604717568, 12060089370317565140003328
Offset: 0

Views

Author

Seiichi Manyama, Feb 17 2017

Keywords

Crossrefs

Cf. A008410 (E_4^2 = E_8), A058550 (E_4^2*E_6 = E_14), A282292 (E_4^2*E_6^2 = E_10^2), A282357 (E_4^2*E_6^3), this sequence (E_4^2*E_6^4).

Programs

  • Mathematica
    terms = 13;
    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}];
    E4[x]^2*E6[x]^4 + O[x]^terms // CoefficientList[#, x]& (* Jean-François Alcover, Feb 27 2018 *)
Previous Showing 31-40 of 45 results. Next