Results 111 to 120 of about 208 (162)
Combinatorics Of RNA Secondary Structures
, 1996 Secondary structures of polynucleotides can be view as a certain class of planar vertex-labeled graphs. We construct recursion formulae enumerating various sub-classes of these graphs as well as certain structural elements (sub-graphs).
Ivo L. Hofacker +2 more
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Some zero-sum constants with weights
, 2008 . For an abelian group G, the Davenport constant D(G) is defined to be the smallest natural number k such that any sequence of k elements in G has a non-empty subsequence whose sum is zero (the identity element).
S. D. Adhikari +2 more
core
Exponential generating function of hyperharmonic numbers indexed by arithmetic progressions
Open Mathematics, 2013 Mező István
doaj +1 more source
Three enumeration formulas of standard young tableaux of truncated shapes
, 2019 In this paper we consider the enumeration of three kinds of standard Young tableaux (SYT) of truncated shapes by use of the method of multiple integrals.
Sun, Ping
core
Finite automata, probabilistic method, and occurrence enumeration of a pattern in words and permutations. [PDF]
SIAM J Discret Math, 2020 Mansour T, Rastegar R, Roitershtein A.
europepmc +1 more source
Permutations Which Are the Union of an Increasing and a Decreasing Subsequence
, 1998 It is shown that there are # 2n n # - # n-1 m=0 2 n-m-1 # 2m m # permutations which are the union of an increasing sequence and a decreasing sequence.
M. D. Atkinson
core
The Bricklayer Problem And The Strong Cycle Lemma
, 1998 this paper, we solve a counting problem about building stacks of such blocks, which we call bricks. We have a linear base of length m on which we can place bricks. The bricks sitting directly on the base can start at any integer position, as long as they
Douglas B. West, Hunter S. Snevily
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Two explicit formulas for the generalized Motzkin numbers. [PDF]
J Inequal Appl, 2017 Zhao JL, Qi F.
europepmc +1 more source
Counting and sampling gene family evolutionary histories in the duplication-loss and duplication-loss-transfer models. [PDF]
J Math Biol, 2020 Chauve C, Ponty Y, Wallner M.
europepmc +1 more source
, 2004 We revisit the pills problem proposed by Knuth and McCarthy. In a bottle there are m large pills and n small pills. The large pill is equivalent to two small pills. Every day a person chooses a pill at random.
Prodinger, Helmut +1 more
core