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.

A218657 Hilltop maps: number of n X 2 binary arrays indicating the locations of corresponding elements not exceeded by any king-move neighbor in a random 0..1 n X 2 array.

Table of values

n a(n)
1 3
2 15
3 57
4 225
5 891
6 3519
7 13905
8 54945
9 217107
10 857871
11 3389769
12 13394241
13 52925643
14 209128959
15 826346529
16 3265203393
17 12902036643
18 50980759695
19 201443999193
20 795980386593
21 3145215436443
22 12427919466687
23 49107345869169

List of values

[3, 15, 57, 225, 891, 3519, 13905, 54945, 217107, 857871, 3389769, 13394241, 52925643, 209128959, 826346529, 3265203393, 12902036643, 50980759695, 201443999193, 795980386593, 3145215436443, 12427919466687, 49107345869169]

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

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