cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A243873 Number of Dyck paths of semilength n having exactly 3 (possibly overlapping) occurrences of the consecutive steps UDUUUDDDUD (with U=(1,1), D=(1,-1)).

Table of values

n a(n)
13 1
14 5
15 23
16 105
17 472
18 2118
19 9446
20 41847
21 184256
22 806740
23 3514298
24 15238732
25 65803650
26 283077978
27 1213561196
28 5186141801
29 22098720181
30 93913940321
31 398127653185
32 1683928072645
33 7107304159469
34 29938529102885
35 125880340885997
36 528371537192555
37 2214227613719264

List of values

[1, 5, 23, 105, 472, 2118, 9446, 41847, 184256, 806740, 3514298, 15238732, 65803650, 283077978, 1213561196, 5186141801, 22098720181, 93913940321, 398127653185, 1683928072645, 7107304159469, 29938529102885, 125880340885997, 528371537192555, 2214227613719264]

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement.