A128808 Coefficients of the invariant of degree 20 associated with the icosahedral group.

-1, 228, -494, -228, -1

Offset

0,2

References

A. Erdelyi, Higher Transcendental Functions, McGraw-Hill, 1955, Vol. 3, p. 11.

F. Klein, Lectures on the Icosahedron ..., 2nd Rev. Ed., 1913; reprinted by Dover, NY, 1956; see p. 61.

S. Mukai, An Introduction to Invariants and Moduli, Cambridge, 2003; see p. 19.

Links

Table of n, a(n) for n=0..4.

Example

H = -(x^20 + y^20) + 228*(x^15*y^5 - x^5*y^15) - 494*x^10*y^10.

Crossrefs

Cf. A128809. The third invariant (which does not have its own entry) is f = x*y*(x^10 + 11*x^5*y^5 - y^10).

Sequence in context: A252228 A252221 A154519 * A043411 A172531 A258557

Adjacent sequences: A128805 A128806 A128807 * A128809 A128810 A128811

Keyword

sign,fini,full

Author

N. J. A. Sloane, Apr 10 2007

Status

approved