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.

A027138 a(n) = Sum_{k=0..2n} (k+1) * A027113(n, 2n-k).

Table of values

n a(n)
1 1
2 7
3 26
4 85
5 264
6 803
7 2422
8 7281
9 21860
10 65599
11 196818
12 590477
13 1771456
14 5314395
15 15943214
16 47829673
17 143489052
18 430467191
19 1291401610
20 3874204869
21 11622614648
22 34867843987
23 104603532006
24 313810596065
25 941431788244
26 2824295364783
27 8472886094402

List of values

[1, 7, 26, 85, 264, 803, 2422, 7281, 21860, 65599, 196818, 590477, 1771456, 5314395, 15943214, 47829673, 143489052, 430467191, 1291401610, 3874204869, 11622614648, 34867843987, 104603532006, 313810596065, 941431788244, 2824295364783, 8472886094402]