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.

A001818 Squares of double factorials: (1*3*5*...*(2n-1))^2 = ((2*n-1)!!)^2.

Table of values

n a(n)
0 1
1 1
2 9
3 225
4 11025
5 893025
6 108056025
7 18261468225
8 4108830350625
9 1187451971330625
10 428670161650355625
11 189043541287806830625
12 100004033341249813400625
13 62502520838281133375390625
14 45564337691106946230659765625
15 38319607998220941779984862890625

List of values

[1, 1, 9, 225, 11025, 893025, 108056025, 18261468225, 4108830350625, 1187451971330625, 428670161650355625, 189043541287806830625, 100004033341249813400625, 62502520838281133375390625, 45564337691106946230659765625, 38319607998220941779984862890625]