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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A029830 Eisenstein series E_20(q) (alternate convention E_10(q)), multiplied by 174611.

Original entry on oeis.org

174611, 13200, 6920614800, 15341851377600, 3628395292275600, 251770019531263200, 8043563916910526400, 150465416446925500800, 1902324110996589786000, 17831242688625346952400, 132000251770026451864800, 807299993919072011054400, 4217144038884527916580800, 19297347832955888660949600
Offset: 0

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Author

Keywords

References

  • J.-P. Serre, Course in Arithmetic, Chap. VII, Section 4.

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), this sequence (174611*E_20), A279893 (77683*E_22), A029831 (236364091*E_24).
Cf. A282015 (E_4^5), A282292 (E_4^2*E_6^2 = E_10^2).

Programs

  • Mathematica
    terms = 14;
    E20[x_] = 174611 + 13200*Sum[k^19*x^k/(1 - x^k), {k, 1, terms}];
    E20[x] + O[x]^terms // CoefficientList[#, x]& (* Jean-François Alcover, Feb 27 2018 *)
  • PARI
    a(n)=if(n<1,174611*(n==0),13200*sigma(n,19))

Formula

a(n) = 53361*A282015(n) + 121250*A282292(n). - Seiichi Manyama, Feb 11 2017

A288989 Denominators of coefficients in expansion of E_14/E_12.

Original entry on oeis.org

1, 691, 477481, 329939371, 227988105361, 157539780804451, 108859988535875641, 75222252078290067931, 51978576186098436940321, 35917196144594019925761811, 24818782535914467768701411401, 17149778732316897228172675278091
Offset: 0

Views

Author

Seiichi Manyama, Jun 21 2017

Keywords

Examples

			E_14/E_12 = 1 - 82104/691 * q - 181275671592/477481 * q^2  + 1327007921039904/329939371 * q^3 + 16726528971891002133912/227988105361 * q^4 + ... .
		

Crossrefs

Cf. A288472 (numerators).
Cf. A029828, A058550 (E_14).

Programs

  • Mathematica
    terms = 12;
    E14[x_] = 1 - 24*Sum[k^13*x^k/(1 - x^k), {k, 1, terms}];
    E12[x_] = 1 + (65520/691)*Sum[k^11*x^k/(1 - x^k), {k, 1, terms}];
    E14[x]/E12[x] + O[x]^terms // CoefficientList[#, x]& // Denominator (* Jean-François Alcover, Feb 26 2018 *)

A279892 Eisenstein series E_18(q) (alternate convention E_9(q)), multiplied by 43867.

Original entry on oeis.org

43867, -28728, -3765465144, -3709938631392, -493547047383096, -21917724609403728, -486272786232443616, -6683009405824511424, -64690198594597187640, -479102079577959825624, -2872821917728374840144, -14520482234727711482016, -63736746640768788267744
Offset: 0

Views

Author

Seiichi Manyama, Dec 22 2016

Keywords

References

  • J.-P. Serre, Course in Arithmetic, Chap. VII, Section 4.

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), this sequence (43867*E_18), A029830 (174611*E_20), A279893 (77683*E_22), A029831 (236364091*E_24).
Cf. A282000 (E_4^3*E_6), A282253 (E_6^3).

Programs

  • Mathematica
    terms = 13;
    E18[x_] = 43867 - 28728*Sum[k^17*x^k/(1 - x^k), {k, 1, terms}];
    E18[x] + O[x]^terms // CoefficientList[#, x]& (* Jean-François Alcover, Feb 26 2018 *)

Formula

G.f.: 43867 - 28728 * Sum_{i>=1} sigma_17(i)q^i where sigma_17(n) is A013965.
a(n) = 38367*A282000(n) + 5500*A282253(n). - Seiichi Manyama, Feb 11 2017

A279893 Eisenstein series E_22(q) (alternate convention E_11(q)), multiplied by 77683.

Original entry on oeis.org

77683, -552, -1157628456, -5774114968608, -2427722831757864, -263214111328125552, -12109202528761173024, -308317316973972772416, -5091303792066668003880, -60399282006368937251976, -552000263214112485753456, -4084937969230504375869024, -25394838301602325644596256, -136379620048544616772836528, -646588586243917921590531648
Offset: 0

Views

Author

Seiichi Manyama, Dec 22 2016

Keywords

References

  • J.-P. Serre, Course in Arithmetic, Chap. VII, Section 4.

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), this sequence (77683*E_22), A029831 (236364091*E_24).
Cf. A282047 (E_4^4*E_6), A282328 (E_4*E_6^3).

Programs

  • Mathematica
    terms = 15;
    E22[x_] = 77683 - 552*Sum[k^21*x^k/(1 - x^k), {k, 1, terms}];
    E22[x] + O[x]^terms // CoefficientList[#, x]& (* Jean-François Alcover, Feb 26 2018 *)

Formula

G.f.: 77683 - 552 * Sum_{i>=1} sigma_21(i)q^i where sigma_21(n) is A013969.
a(n) = 57183*A282047(n) + 20500*A282328(n). - Seiichi Manyama, Feb 12 2017

A282356 Eisenstein series E_26(q) (alternate convention E_13(q)), multiplied by 657931.

Original entry on oeis.org

657931, -24, -805306392, -20334926626656, -27021598569529368, -7152557373046875024, -682326933054044766048, -32185646871935157619392, -906694391732570450559000, -17229551704624797057112632, -240000007152557373852181392
Offset: 0

Views

Author

Seiichi Manyama, Feb 13 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), this sequence (657931*E_26).
Cf. A282048 (E_4^5*E_6), A282357 (E_4^2*E_6^3).

Programs

  • Mathematica
    terms = 11;
    E26[x_] = 657931 - 24*Sum[k^25*x^k/(1 - x^k), {k, 1, terms}];
    E26[x] + O[x]^terms // CoefficientList[#, x]& (* Jean-François Alcover, Feb 26 2018 *)

Formula

a(n) = 392931*A282048(n) + 265000*A282357(n).

A056947 Theta series of nonexistent Niemeier lattice of Coxeter number 1.

Original entry on oeis.org

1, 24, 195984, 16779168, 397998672, 4629497040, 34417510848, 187489533504, 814881802320, 2975548760568, 9486548517600, 27052958750688, 70486228096704, 169931081461008, 384163595996544, 820166650027200, 1668890114013264, 3249630946490544, 6096882726702288
Offset: 0

Views

Author

Kok Seng Chua (chuaks(AT)ihpc.nus.edu.sg), Jul 17 2000

Keywords

Examples

			G.f.: 1 + 24*q + 195984*q^2 + 16779168*q^3 + ...
		

References

  • J. H. Conway and N. J. A. Sloane, Sphere Packings, Lattices and Groups, Springer-Verlag, 1988.

Crossrefs

Programs

  • Sage
    d = CuspForms(1, 12).0.q_expansion(20);
    e =(eisenstein_series_qexp(12,20, normalization='integral'))
    list(e/691-(48936/691)*d) # Andy Huchala, Jul 10 2021

Formula

E_12(z)+(24h-c12)*D(12) where D(12) is unique cusp form of weight 12, c12=(2*Pi)^12/(zeta(12)*gamma(12)) and h=1.
a(n) = (A029828(n) - 48936*A000594(n))/691. - Andy Huchala, Jul 11 2021

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

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).

A288472 Numerators of coefficients in expansion of E_14/E_12.

Original entry on oeis.org

1, -82104, -181275671592, 1327007921039904, 16726528971891002133912, -212292443057353273999454544, -1528649681810950691089095375538848, 27164473060529924968213209402868250688, 139687438912977894660348148674573721130447640
Offset: 0

Views

Author

Seiichi Manyama, Jun 21 2017

Keywords

Examples

			E_14/E_12 = 1 - 82104/691 * q - 181275671592/477481 * q^2  + 1327007921039904/329939371 * q^3 + 16726528971891002133912/227988105361 * q^4 + ... .
		

Crossrefs

Cf. A288989 (denominators).
Cf. A029828, A058550 (E_14).

Programs

  • Mathematica
    terms = 9;
    E14[x_] = 1 - 24*Sum[k^13*x^k/(1 - x^k), {k, 1, terms}];
    E12[x_] = 1 + (65520/691)*Sum[k^11*x^k/(1 - x^k), {k, 1, terms}];
    E14[x]/E12[x] + O[x]^terms // CoefficientList[#, x]& // Numerator (* Jean-François Alcover, Feb 26 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.
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