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.

A137636 a(n) = Sum_{k=0..n} C(2k+1,k)*C(2k+1,n-k) ; equals row 1 of square array A137634; also equals the convolution of A137635 and A073157.

Table of values

n a(n)
0 1
1 4
2 19
3 94
4 474
5 2431
6 12609
7 65972
8 347524
9 1840680
10 9792986
11 52296799
12 280163091
13 1504969409
14 8103433329
15 43722788132
16 236340999038
17 1279602656590
18 6938126362948
19 37668424608552
20 204751452911832
21 1114151447523038

List of values

[1, 4, 19, 94, 474, 2431, 12609, 65972, 347524, 1840680, 9792986, 52296799, 280163091, 1504969409, 8103433329, 43722788132, 236340999038, 1279602656590, 6938126362948, 37668424608552, 204751452911832, 1114151447523038]

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement.