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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A319309 Expansion of theta_4(q)^24 in powers of q = exp(Pi i t).

Original entry on oeis.org

1, -48, 1104, -16192, 170064, -1362336, 8662720, -44981376, 195082320, -721175536, 2319457632, -6631997376, 17231109824, -41469483552, 93703589760, -200343312768, 407488018512, -793229226336, 1487286966928, -2697825744960, 4744779429216, -8110465650176
Offset: 0

Views

Author

Seiichi Manyama, Sep 16 2018

Keywords

Crossrefs

theta_4(q)^b: A002448 (b=1), A104794 (b=2), A213384 (b=3), A096727 (b=4), A035016 (b=8), A286346 (b=12), A319307 (b=16), A319308 (b=20), this sequence (b=24), A319310 (b=28).
Cf. A000156.

Formula

Expansion of eta(q)^48 / eta(q^2)^24 in powers of q.

A127308 Number of ways of writing the n-th prime prime(n) as a sum of 24 squares.

Original entry on oeis.org

1104, 16192, 1362336, 44981376, 6631997376, 41469483552, 793229226336, 2697825744960, 22063059606912, 282507110257440, 588326886375936, 4119646755044256, 12742799887509216, 21517654506205632, 57242599902057216
Offset: 1

Views

Author

Jonathan Sondow, Jan 10 2007

Keywords

Comments

|a(n) - (16/691)*(prime(n)^11 + 1)| <= (66304/691)*sqrt(prime(n)^11) (proved by Deligne).

Examples

			For prime(1) = 2, two of the 24 squares are (+-1)^2 and the other 22 are 0^2, so a(1) = 2*2*binomial(24,2) = 4*276 = 1104.
		

References

  • E. Grosswald, Representations of Integers as Sums of Squares, Springer-Verlag, NY, 1985, p. 107.
  • Barry Mazur, Controlling our errors, Nature 443, 7 (2006) 38-40.

Crossrefs

Programs

  • Mathematica
    Table[SquaresR[24, Prime[n]], {n, 1, 70}]
    Table[Abs[16/691 (p^11 + 1) + 33152/691 RamanujanTau[p]], {p, Prime@Range@70}] (* Giorgos Kalogeropoulos, Dec 15 2022 *)

Formula

a(n) = A000156(prime(n)).
a(n) ~ (16/691)*(prime(n)^11 + 1) as n -> oo.
a(n) = (16/691)*(prime(n)^11+1) + (33152/691)*tau(prime(n)) for n>1 where tau = A000594. - Giorgos Kalogeropoulos, Dec 15 2022
Showing 1-2 of 2 results.