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.

A268070 Number of nX2 0..3 arrays with every repeated value in every row and column unequal to the previous repeated value, and new values introduced in row-major sequential order.

Table of values

n a(n)
1 2
2 15
3 159
4 2191
5 30295
6 421471
7 5797959
8 79367143
9 1079774311
10 14630901175
11 197520668295
12 2659138662775
13 35714778101863
14 478783751931415
15 6408527754114375
16 85670414104756855
17 1144076540594898727

List of values

[2, 15, 159, 2191, 30295, 421471, 5797959, 79367143, 1079774311, 14630901175, 197520668295, 2659138662775, 35714778101863, 478783751931415, 6408527754114375, 85670414104756855, 1144076540594898727]

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

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