A113922 G.f.: (1+14*x+x^2)^3/((1-x))^4.

1, 46, 769, 5632, 18688, 44032, 85760, 147968, 234752, 350208, 498432, 683520, 909568, 1180672, 1500928, 1874432, 2305280, 2797568, 3355392, 3982848, 4684032, 5463040, 6323968, 7270912, 8307968, 9439232, 10668800, 12000768, 13439232, 14988288, 16652032

Offset

0,2

Comments

Coefficient expansion of the elliptical invariant for the cube.

References

Gareth Jones and David Singerman, Bull. London Math. Soc. 28, (1996) pages 561-590 (S_4 group invariant on page 585)

H. McKean and V. Moll. Elliptic Curves, Camb. Univ. Press, p. 22.

Links

Table of n, a(n) for n=0..30.

Index entries for linear recurrences with constant coefficients, signature (4,-6,4,-1).

Formula

a(n) = 256*(n-1)*(8*n^2 - 16*n + 9)/3 for n >= 3. - Emeric Deutsch, Apr 02 2006

Maple

a:=proc(n) if n=0 then 1 elif n=1 then 46 elif n=2 then 769 else 256*(n-1)*(8*n^2-16*n+9)/3 fi end: seq(a(n), n=0..30); # Emeric Deutsch, Apr 02 2006

Crossrefs

Sequence in context: A078156 A341428 A066405 * A160067 A156842 A078427

Adjacent sequences: A113919 A113920 A113921 * A113923 A113924 A113925

Keyword

nonn,easy

Author

Roger L. Bagula, Jan 29 2006

Extensions

Corrected, edited and extended by N. J. A. Sloane, Mar 31 2006, Aug 13 2008

Status

approved