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.

A277247 a(n) = Sum_{k=0..floor(n/2)} binomial(n, k)^2.

Table of values

n a(n)
0 1
1 1
2 5
3 10
4 53
5 126
6 662
7 1716
8 8885
9 24310
10 124130
11 352716
12 1778966
13 5200300
14 25947612
15 77558760
16 383358645
17 1166803110
18 5719519850
19 17672631900
20 85990654178
21 269128937220
22 1300866635172
23 4116715363800
24 19780031677718
25 63205303218876
26 302045506654052

List of values

[1, 1, 5, 10, 53, 126, 662, 1716, 8885, 24310, 124130, 352716, 1778966, 5200300, 25947612, 77558760, 383358645, 1166803110, 5719519850, 17672631900, 85990654178, 269128937220, 1300866635172, 4116715363800, 19780031677718, 63205303218876, 302045506654052]

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

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