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.

A060552 a(n) is the number of distinct (modulo geometric D3-operations) nonsymmetric (no reflective nor rotational symmetry) patterns which can be formed by an equilateral triangular arrangement of closely packed black and white cells satisfying the local matching rule of Pascal's triangle modulo 2, where n is the number of cells in each edge of the arrangement. The matching rule is such that any elementary top-down triangle of three neighboring cells in the arrangement contains either one or three white cells.

Table of values

n a(n)
1 0
2 0
3 0
4 1
5 2
6 7
7 14
8 35
9 70
10 154
11 310
12 650
13 1300
14 2666
15 5332
16 10788
17 21588
18 43428
19 86856
20 174244
21 348488
22 697992
23 1396040
24 2794120
25 5588240
26 11180680
27 22361360
28 44730896
29 89462032
30 178940432
31 357880864
32 715794960

List of values

[0, 0, 0, 1, 2, 7, 14, 35, 70, 154, 310, 650, 1300, 2666, 5332, 10788, 21588, 43428, 86856, 174244, 348488, 697992, 1396040, 2794120, 5588240, 11180680, 22361360, 44730896, 89462032, 178940432, 357880864, 715794960]