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.

A222115 a(n) = 1 + Sum_{k=1..n} binomial(n,k) * sigma(k).

Table of values

n a(n)
1 2
2 6
3 17
4 46
5 117
6 285
7 674
8 1558
9 3536
10 7911
11 17503
12 38377
13 83501
14 180480
15 387882
16 829606
17 1766999
18 3749766
19 7931115
20 16724871
21 35173778
22 73794661
23 154485528
24 322771345
25 673155142
26 1401536935
27 2913490376
28 6047714600
29 12536770559
30 25956242580
31 53678385267
32 110889844998

List of values

[2, 6, 17, 46, 117, 285, 674, 1558, 3536, 7911, 17503, 38377, 83501, 180480, 387882, 829606, 1766999, 3749766, 7931115, 16724871, 35173778, 73794661, 154485528, 322771345, 673155142, 1401536935, 2913490376, 6047714600, 12536770559, 25956242580, 53678385267, 110889844998]

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

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