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A005797 Expansion of Jacobi nome q in terms of parameter m/16.
(Formerly M4561)
4
0, 1, 8, 84, 992, 12514, 164688, 2232200, 30920128, 435506703, 6215660600, 89668182220, 1305109502496, 19138260194422, 282441672732656, 4191287776164504, 62496081197436736, 935823746406530603 (list; graph; refs; listen; history; internal format)
OFFSET

0,3

REFERENCES

M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards Applied Math.Series 55, Tenth Printing, 1972, p. 591.

B. C. Berndt, Ramanujan's theory of theta-functions, Theta functions: from the classical to the modern, Amer. Math. Soc., Providence, RI, 1993, pp. 1-63. MR 94m:11054.

C. L. Mallows (colinm(AT)research.avayalabs.com), personal communication.

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

LINKS

M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards, Applied Math. Series 55, Tenth Printing, 1972 [alternative scanned copy].

M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards Applied Math.Series 55, Tenth Printing, 1972, p. 591.

Index entries for reversions of series

FORMULA

G.f.: q = q(m) = Sum_{n=0..oo} a(n) * (m/16)^n.

G.f.: exp( -pi * agm(1, sqrt(1 - 16 * x) / agm(1, sqrt( 16*x )))).

EXAMPLE

x + 8*x^2 + 84*x^3 + 992*x^4 + 12514*x^5 + 164688*x^6 + 2232200*x^7 + ...

MATHEMATICA

a[ n_] := SeriesCoefficient[ EllipticNomeQ[ 16 x], {x, 0 , n}] (* Michael Somos, Jul 11 2011 *)

PROG

(PARI) {a(n) = if( n<1, 0, polcoeff( serreverse( x * prod(k=1, n-1, (1 + x^k)^(-1)^k, 1 + x * O(x^n))^8), n))} /* Michael Somos, Jul 19 2002 */

(PARI) {a(n) = local(A, m); if( n<1, 0, m=1; A = x + O(x^2); while( m<n, m*=2; A = sqrt( subst(A, x, x^2)); A /= (1 + 4*A)^2); polcoeff( serreverse(A), n))} /* Michael Somos, Mar 18 2003 */

CROSSREFS

Reversion of A005798. Cf. A002639.

Sequence in context: A143868 A130591 A048665 * A052659 A113376 A205311

Adjacent sequences:  A005794 A005795 A005796 * A005798 A005799 A005800

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com).

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Last modified February 17 06:27 EST 2012. Contains 205998 sequences.