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.

A293295 a(n) = Sum_{k=1..n} (-1)^(n-k)*hypergeom([k, k-2-n], [], 1).

Table of values

n a(n)
1 1
2 5
3 27
4 142
5 847
6 5817
7 45733
8 405836
9 4012701
10 43733965
11 520794991
12 6726601050
13 93651619867
14 1398047697137
15 22275111534537
16 377278848390232
17 6768744159489913
18 128228860181918421
19 2557808459478878851
20 53585748788874537830
21 1176328664895760953831

List of values

[1, 5, 27, 142, 847, 5817, 45733, 405836, 4012701, 43733965, 520794991, 6726601050, 93651619867, 1398047697137, 22275111534537, 377278848390232, 6768744159489913, 128228860181918421, 2557808459478878851, 53585748788874537830, 1176328664895760953831]

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

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