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.

A381482 a(n) = Sum_{k=0..floor(n/2)} binomial(n,k)^2 * binomial(n-k,k) * 2^k.

Table of values

n a(n)
0 1
1 1
2 9
3 37
4 241
5 1401
6 8961
7 57429
8 377217
9 2509201
10 16876729
11 114600069
12 783903121
13 5397915433
14 37372017489
15 259998843477
16 1816376953857
17 12736545070113
18 89602978644969
19 632223913939557
20 4472680961409201
21 31717890254271321
22 225416254500886689
23 1605197563027768917

List of values

[1, 1, 9, 37, 241, 1401, 8961, 57429, 377217, 2509201, 16876729, 114600069, 783903121, 5397915433, 37372017489, 259998843477, 1816376953857, 12736545070113, 89602978644969, 632223913939557, 4472680961409201, 31717890254271321, 225416254500886689, 1605197563027768917]

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

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