login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A013699 Degree of variety K_{2,n}^2. 4
1, 32, 610, 9842, 147798, 2145600, 30664890, 435668420, 6186432967, 88066807556, 1258885297696, 18084694597452, 261164661944060, 3791317346771584, 55316720239735242, 810944384733610356 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Number of Catalan paths (nonnegative, starting and ending at 0, step +/-1) of 4n+4 steps with all values less than or equal to n+1 (see A080934).

LINKS

Table of n, a(n) for n=1..16.

M. S. Ravi et al., Dynamic pole assignment and Schubert calculus, SIAM J. Control Optimization, 34 (1996), 813-832, esp. p. 825.

PROG

(PARI) K(n, q=2)=(2*n+n*q+2*q)!*sum(j=0, q, ((q-2*j)*(n+2)+1)/(n+j*(n+2))!/(n+1+(q-j)*(n+2))!)

CROSSREFS

Cf. A013698 (q=1), A013700 (q=3), A013701 (q=4), A013702 (q=5).

Sequence in context: A088914 A036903 A208828 * A283279 A004337 A292880

Adjacent sequences:  A013696 A013697 A013698 * A013700 A013701 A013702

KEYWORD

nonn,easy

AUTHOR

Joachim.Rosenthal(AT)nd.edu (Joachim Rosenthal)

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified June 3 03:59 EDT 2020. Contains 334793 sequences. (Running on oeis4.)