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.

A232617 Product of first n odd numbers plus product of first n even numbers: (2n-1)!! + (2n)!!, where k!! = A006882(k).

Table of values

n a(n)
1 3
2 11
3 63
4 489
5 4785
6 56475
7 780255
8 12348945
9 220253985
10 4370620275
11 95498916975
12 2278224696825
13 58917607974225
14 1641787169697675
15 49040157044253375
16 1563094742062478625
17 52953322446161762625
18 1899986948191060603875
19 71977860935783603175375
20 2870913642898706235455625

List of values

[3, 11, 63, 489, 4785, 56475, 780255, 12348945, 220253985, 4370620275, 95498916975, 2278224696825, 58917607974225, 1641787169697675, 49040157044253375, 1563094742062478625, 52953322446161762625, 1899986948191060603875, 71977860935783603175375, 2870913642898706235455625]

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

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