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.

A224669 Number of (n+1) X 2 0..2 matrices with each 2 X 2 subblock idempotent.

Table of values

n a(n)
1 12
2 25
3 41
4 70
5 115
6 189
7 308
8 501
9 813
10 1318
11 2135
12 3457
13 5596
14 9057
15 14657
16 23718
17 38379
18 62101
19 100484
20 162589
21 263077
22 425670
23 688751
24 1114425
25 1803180
26 2917609
27 4720793
28 7638406
29 12359203
30 19997613
31 32356820
32 52354437
33 84711261
34 137065702

List of values

[12, 25, 41, 70, 115, 189, 308, 501, 813, 1318, 2135, 3457, 5596, 9057, 14657, 23718, 38379, 62101, 100484, 162589, 263077, 425670, 688751, 1114425, 1803180, 2917609, 4720793, 7638406, 12359203, 19997613, 32356820, 52354437, 84711261, 137065702]

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

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