# What was Cayley's formula for the number of invariants? (Lost Formula!?)

I need to find Cayley's formula for the number of linearly independent invariants of homogenous polynomials. This is a combinatorial formula. He is believed to have discovered it in 1854. Unfortunately I can't find it online and it is not available in any book that I know of. Note that this formula is different from the formula used for graphs.

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This paper refers to Hilbert's "Theory of algebraic invariants" for 'the well-known Sylvester-Cayley formula', but I don't know whether that's what you're looking for. –  Tara B May 11 '12 at 8:50
Also TA Springer's 'Invariant Theory' from this paper: sciencedirect.com/science/article/pii/S0195669806000916 –  Drew Christianson May 11 '12 at 9:01
Furthermore this entry would seem to imply that the majority of Cayley's work on the topic was published in the ten 'Memoirs on Quantics' (which they mistakenly spell as quanties). Fortunately, all ten are available on JSTOR here. Based on the encyclopedia, the First or Second memoir seems the most likely source for the expression. –  Drew Christianson May 11 '12 at 9:09