# My Erdös Number

Apparently my Erdös number is 5.
The shortest coauthorship path that I know of, between Erdös
and myself, is listed below.
More information about Erdös numbers can be found at
http://www.oakland.edu/enp/.
My thanks to Jerry Grossman for
maintaining the Erdös database and providing me with some
parts of the path below.
In case you're not familiar with Erdös numbers, here is
a brief introduction. Paul Erdös was one of the most
brilliant and prolific mathematicians of the 20th century.
He authored or coauthored (mostly the latter) about 1500
papers. In so doing, he encouraged and promoted the system
of collaboration and coauthorship that has become much
more commonplace in recent years; far fewer mathematical
papers today are written by a single author. ...
Erdös was also one of the most egotistical
mathematicians of the 20th century. He described
anyone who coauthored a paper with him as having
"Erdös number 1"; anyone who coauthored a paper
with one of those people had "Erdös number 2"; and
so on. Following is my path to Erdös:

Paul Erdös -- Erdös number 0

Paul Erdös and Geza Freud:
On orthogonal polynomials with regularly distributed zeros.
*Proc. London Math. Soc. (3)* **29** (1974), 521-537.
MR 54 #8134.
Geza Freud -- Erdös number 1

Geza Freud and Janos Bognar:
Berechnung der gequantelten Energiewerte eines im elektrischen
Felde rotierenden Dipols. (Hungarian. Russian,
German summary)
*Magyar Tud. Akad. Alkalm. Mat. Int. Közl.* **3** (1954), 239--251
(1955). MR 17,852e.
Janos Bognar -- Erdös number 2

Janos Bognar and Paul A. Binding
(also with T. Ja. Azizov
and B. Najman):
Nondegenerate Jordan subspaces of selfadjoint operators in
indefinite spaces. (English. English summary)
*Linear Algebra Appl.* **207** (1994), 37-48.
MR 96c:15003.
Paul A. Binding -- Erdös number 3

D. C. Biles
and P. A. Binding:
On Carathéodory's conditions for the initial value problem.
*Proc. Amer. Math. Soc.*
**125** (1997), no. 5, 1371-1376.
MR 97g:34008.
Daniel C. Biles -- Erdös number 4

Daniel C. Biles and Eric Schechter: Solvability of a finite
or infinite system of discontinuous quasimonotone
differential equations, *Proc.
Amer. Math. Soc.* **128** (2000), 3349-3360.
Eric Schechter -- Erdös number 5