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.

A081866 a(n) = sigma_9(2n-1).

Table of values

n a(n)
1 1
2 19684
3 1953126
4 40353608
5 387440173
6 2357947692
7 10604499374
8 38445332184
9 118587876498
10 322687697780
11 794320419872
12 1801152661464
13 3814699218751
14 7625984925160
15 14507145975870
16 26439622160672
17 46413842369328
18 78815680978608
19 129961739795078
20 208738965677816

List of values

[1, 19684, 1953126, 40353608, 387440173, 2357947692, 10604499374, 38445332184, 118587876498, 322687697780, 794320419872, 1801152661464, 3814699218751, 7625984925160, 14507145975870, 26439622160672, 46413842369328, 78815680978608, 129961739795078, 208738965677816]