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.

A175385 a(n) = numerator of Sum_{i=1..n} binomial(2n-i-1,i-1)/i.

Table of values

n a(n)
1 1
2 3
3 17
4 23
5 61
6 107
7 421
8 1103
9 5777
10 7563
11 19801
12 103681
13 135721
14 355323
15 1860497
16 2435423
17 6376021
18 11128427
19 43701901
20 114413063
21 599074577
22 784198803
23 2053059121
24 10749957121
25 14071876561
26 36840651123
27 192900153617

List of values

[1, 3, 17, 23, 61, 107, 421, 1103, 5777, 7563, 19801, 103681, 135721, 355323, 1860497, 2435423, 6376021, 11128427, 43701901, 114413063, 599074577, 784198803, 2053059121, 10749957121, 14071876561, 36840651123, 192900153617]