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 1-4 of 4 results.

A047805 Duplicate of A008695.

Original entry on oeis.org

1, 288, 189648, 16845696, 397610064, 4630772160, 34415914176, 187485113088, 814904105040, 2975518758816, 9486517914720, 27053099888256, 70486130167488, 169930928938176, 384163702086528
Offset: 0

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Keywords

Comments

Original title: Theta series of Niemeier lattice of type E_6^4.

Crossrefs

Equal to theta series of A_11 D_7 E_6, cf. A008695

Programs

  • Mathematica
    terms = 15; E4[q_] := 1 + 240 Sum[DivisorSigma[3, n]*q^(2 n), {n, 1, terms}]; E6[q_] := 1 - 504 Sum[DivisorSigma[5, n]*q^(2 n), {n, 1, terms}]; s = 3/4 E4[q]^3 + 1/4 E6[q]^2 + O[q]^(3 terms); Partition[ CoefficientList[s, q], 2][[All, 1]][[1 ;; terms]] (* Jean-François Alcover, Jul 06 2017 *)

Formula

This series is the q-expansion of 3/4 E_4(z)^3 + 1/4 E_6(z)^2. Cf. A004009, A013973.

Extensions

More terms and formula in terms of Eisenstein series from Daniel D. Briggs, Nov 25 2011

A008696 Theta series of Niemeier lattice of type D_6^4.

Original entry on oeis.org

1, 240, 190800, 16833600, 397680720, 4630540320, 34416204480, 187485916800, 814900050000, 2975524213680, 9486523478880, 27053074226880, 70486147972800, 169930956669600, 384163682797440, 820166912933760
Offset: 0

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Author

Keywords

Comments

Also the theta series for the Niemeier lattice of type A_9^2 D_6. - clarified by Ben Mares, Sep 13 2022

References

  • J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 407.

Crossrefs

Programs

  • Mathematica
    terms = 15; th = EllipticTheta; E4 = 1 + 240*Sum[k^3*(q^k/(1 - q^k)), {k, 1, terms}] + O[q]^terms; E6 = th[2, 0, q]^12 + th[3, 0, q]^12 - 33*th[2, 0, q]^4*th[3, 0, q]^4*(th[2, 0, q]^4 + th[3, 0, q]^4); CoefficientList[ (13/18)*E4^3 + (5/18)*E6^2 + O[q]^terms, q] (* Jean-François Alcover, Jul 05 2017 *)

Formula

This series is the q-expansion of (13*E_4(z)^3 + 5*E_6(z)^2)/18. - Daniel D. Briggs, Nov 25 2011

A008694 Theta series of Niemeier lattice of type A_12^2.

Original entry on oeis.org

1, 312, 189072, 16851744, 397574736, 4630888080, 34415769024, 187484711232, 814906132560, 2975516031384, 9486515132640, 27053112718944, 70486121264832, 169930915072464, 384163711731072
Offset: 0

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Author

Keywords

References

  • J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 407.

Crossrefs

Programs

  • Mathematica
    terms = 15; E4[q_] := 1 + 240 Sum[DivisorSigma[3, n]*q^(2 n), {n, 1, terms}]; E6[q_] := 1 - 504 Sum[DivisorSigma[5, n]*q^(2 n), {n, 1, terms}]; s = 55/72 E4[q]^3 + 17/72 E6[q]^2 + O[q]^(3 terms); Partition[ CoefficientList[s, q], 2][[All, 1]][[1 ;; terms]] (* Jean-François Alcover, Jul 06 2017 *)

Formula

This series is the q-expansion of (55*E_4(z)^3 + 17*E_6(z)^2)/72. - Daniel D. Briggs, Nov 25 2011

A055757 Jacobi form of weight 12 and index 1 for Niemeier lattice of type E_6^4 or A_11 D_7 E_6.

Original entry on oeis.org

1, 0, 0, 20, 246, 0, 0, 30624, 127908, 0, 0, 3699612, 9190616, 0, 0, 95498592, 188170398, 0, 0, 1143506364, 1960018920, 0, 0, 8506347552, 13291928232, 0, 0, 45759995408, 67075871808, 0, 0, 195397296192, 272568671892, 0, 0
Offset: 0

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Author

Kok Seng Chua (chuaks(AT)ihpc.nus.edu.sg), Jul 12 2000

Keywords

References

  • Eichler and Zagier, The Theory of Jacobi Forms, Birkhauser,1985.

Crossrefs

Formula

E_8*E_{4, 1}-36*phi_12.
G.f.: b(z) - 36*c(z) where b(z) is the g.f. for A055747 and c(z) is the g.f. for A003785. - Sean A. Irvine, Apr 05 2022
Showing 1-4 of 4 results.