- Author of sequence A189711,
Number of non-monotonic functions from [k] to [n-k], April 25, 2011.
- Author of sequence A188441, Size-k subsets of [n] that
contain no consecutive integers;
binomial coefficients C(n+1-k,k),
March
31, 2011.
- Author of sequence A188440,
Triangle T(n,k) read by rows: number of size-k antisymmetric subsets
of
{1,2,...,n}, March 31, 2011.
- Author of sequence A187105, number
of height-2-restricted finite functions, March 4, 2011.
- Author of sequence A186526,
permutations on n elements with exactly k 3-cycles; provided
interpretation,
formula, example, and references. Feb 23,
2011
- Author of sequence
A058127, the number of acyclic functions, November 14, 2000.
- Author of sequence
A058128, number of acyclic-function digraphs
on n vertices, November 14, 2000.
- Author of sequence A057693,
the number of permutations on n letters that have
only cycles of length 3 or less,
October 20, 2000.
- Author of sequence A122974,
Triangle T(n,k), the number of permutations on n
elements that have
no cycles of length k, October 27, 2006.
- Contribution to sequence A006331, Maximum accumulated number of
electrons at energy level n;
provided new description,
example, and link to associated paper,
April 25, 2011.
- Contribution to sequence A000169, Number of labeled rooted trees
with n nodes; provided new explanation
and example, April 21,
2011.
- Conribution to sequence A008279,
Number of permutations of n things taken k at a time; provided new
description,
example, Maple code, and link to associated paper, April
20,
2011.
- Contribution to sequence A059481, The triangle T(n,k) =
binomial(n+k-1,k) read by rows; provided new
interpretation of
sequence,
example, and link to associated paper, April 7, 2011.
- Contribution to sequence A007318, Pascal's triangle (of binomial
coefficients;
provided new intrepretation and example, April 7,
2001.
- Contribution to sequence
A161680, Binomial(n,2): number of
size-2 subsets of {0,1,...,n} that contain
no consecutive integers;
contributed new description, example, and link, March 30, 2011.
- Contribution
to sequence A000272,
Number of trees on n labeled nodes; contibuted new interpretation,
example, generating function, and link, March 2, 2011.
- Contribution to sequence A141765, width-2-restricted finite
functions; contributed description, formula,
example, and link,
February
15, 2011.
-
Contribution to sequence A094587,
permutations on n letters with exactly k+1 cycles and with the
first
k+1
letters in separate cycles, January 24, 2011.
- Contribution to sequence A130534, unsigned Stirling numbers;
contributed description, formula, and link on January 25, 2011.
- Contribution to sequence A000680,
interpretation of sequences as number of functions with preimage
constraints;
also contributed recursive formula, November 17,
2009.
- Contribution to sequence A000027,
the natural numbers; formulation of sequence as a triangular array,
November 19, 2009.
- Contributor to sequence A000108
with ball/box
intepretation of Catalan numbers, December 4, 2006.
- Contributor to sequence
A000110; intepretation of the Bell numbers as the
number of
functions with finite domain and codomain
satisfying certain
conditions, February 20, 2006.
- Contributor to sequence A000984;
intepretation of
central binomial coefficients as the number of direct routes on a city
grid
from home to Granny's, October 27, 2006
- Number of ordered ballots resulting in an election tie -
contributed interpretation of sequence A002426,
(central trinomial
coefficients), October 8, 2004.
- Number of n x 2 simple rectangular mazes - contributed
interpretation for sequence
A001353,
[a(n)=4a(n-1)-a(n-2) with a(0)=0 and a(1)=1], October 4,
2006.
- Number of chain gangs for a finite set - contributed interpretation
of integer
sequence
A000262,
number of "sets of lists", February 22, 2007.
- Contributed formula a(n)=phi^(2n)+phi^(-2n), where phi is the golden
ratio, for integer sequence
A005248
(bisection of Lucas
numbers), July 24, 2003.
-
Contributed formula and function count interpretation for sequence A000392,
Stirling
numbers of the second
kind S(n,3), February 20, 2007.
- Number of injective functions - contributed interpretation for
sequence A068424,
triangle of falling factorials, October 18, 2007
- Comment and formula contribution to sequence
A005225, number of
permutations of length n with equal cycyles
- Contributor to sequence A016116,
interpretation
of sequence as the number of symmetric subsets of
{1,2,...,n}, October 27, 2009.
- Contributor to sequence A074909
(running sum of Pascal's triangle), interpretation of sequence as number
of increasing
acyclic functions, March 14, 2008.
- Contributor to sequence A004247,
interpretation of sequence as variance of a binary data set and a number
of ways to form
opposite-sex dance couples, November 10, 2009.
- Contributor to sequence A105278,
interpretation of sequence as the number of posets consisting entirely of
chains, February 22, 2007.