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.

A229727 Numerator of Sum_{k=1..2n+1} 2^k/k.

Table of values

n a(n)
0 2
1 20
2 256
3 4832
4 42496
5 1467392
6 62836736
7 42790912
8 2535587840
9 170851041280
10 3070050172928
11 256460544016384
12 4697678227177472
13 52001663422038016
14 5598478396465086464
15 647670579588837146624
16 2427980359983876276224
17 9138219784535816536064
18 1277040945143933271277568

List of values

[2, 20, 256, 4832, 42496, 1467392, 62836736, 42790912, 2535587840, 170851041280, 3070050172928, 256460544016384, 4697678227177472, 52001663422038016, 5598478396465086464, 647670579588837146624, 2427980359983876276224, 9138219784535816536064, 1277040945143933271277568]