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.

A247473 Numbers of the form 2^k (k>=0) that are a sum of divisors of n for some n.

Table of values

n a(n)
1 1
2 4
3 8
4 32
5 128
6 256
7 512
8 1024
9 4096
10 8192
11 16384
12 32768
13 65536
14 131072
15 262144
16 524288
17 1048576
18 2097152
19 4194304
20 8388608
21 16777216
22 33554432
23 67108864
24 134217728
25 268435456
26 536870912
27 1073741824
28 2147483648
29 4294967296
30 8589934592
31 17179869184
32 34359738368

List of values

[1, 4, 8, 32, 128, 256, 512, 1024, 4096, 8192, 16384, 32768, 65536, 131072, 262144, 524288, 1048576, 2097152, 4194304, 8388608, 16777216, 33554432, 67108864, 134217728, 268435456, 536870912, 1073741824, 2147483648, 4294967296, 8589934592, 17179869184, 34359738368]