## Errata

Various people have been kind enough to point out some errors in my mathematics encyclopedia. Thanks especially to Freeman Dyson, Warren Johnson, and John Pinto. If you own a copy, you might care to make a note of the corrections in the margins. If you spot any mistakes yourself, I'd be happy to add them to the list.

Jan. 21, 2006

In the entry: Abel, Niels Henrik

It is stated that Galois died in a sword fight. In fact, the duel was fought with pistols.

In the entry: Bernoulli numbers

"The first few Bernoulli numbers are...." should read "The first few nonzero Bernoulli numbers are...."

In the entry: Cauchy, Augustin Louis

"George" Cayley should be "Arthur" Cayley.

In the entry: God

"Charles" Jacobi should "Karl" Jacobi

In the entry: Hamilton, William Rowan

"Wernher" Schrodinger should be "Erwin" Schrodinger. (Wernher being Heisenberg's first name.)

In the entry: Hermite, Charles

It is stated that Hermite "studied a class of differential equations now known as Hermite polynomials." In fact, Hermite polynomials are the solutions that he found to these equations.

In the entry: Ramanujan, Srinivasa Aaiyangar

The full name is spelled and ordered incorrectly. P.V. Seshu Aiyar and R. Ramachandra Rao in their obituary of R. render his name as Srinivasa Ramanujan Aiyangar. Robert Kanigel In his biography of R. gives his name as Srinivasa Ramanujan Iyengar.

In the entry: special functions

"Lagrange" polynomials should read "Legendre" polynomials.

In the entry: triangular numbers

"Every triangular number is a perfect number" should read "Every even perfect number is a triangular number."

Jan. 23, 2006

In the entry: finite-state automaton

The term "regular expressions" should not be in bold.

Jan. 26, 2006

In the entry: Ackermann function

The formulas for the A's are correct but the conditions under which each is used is incorrect. The first one says to use it for n=0; this should be n>=0. The second says to use it for m=1; this should be m>=1. The final one says m, n=1; this should be m, n>=1.

In the entry: algorithm

"Liebniz" should be "Leibniz."

In the entry: cannonball problem

In the phrase, "So, when, in 1909, Johannes Kepler wanted some advice..." the correct date should be 1609 (!).

In the entry: Knuth up-arrow notation

In the definition of m^^n (where ^ is the up arrow) the brace should include the bottom m also. (For clarity, it should be added that m^^n=m^m^m^m...^m (n terms) and also that Knuth up-arrows are evaluated from right to left.)