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.

A227022 Number of nX3 (0,1,2) arrays of permanents of 2X2 subblocks of some (n+1)X4 binary array with rows and columns of the latter in lexicographically nondecreasing order.

Table of values

n a(n)
1 12
2 72
3 335
4 1366
5 4948
6 16115
7 47659
8 129463
9 326522
10 771653
11 1722005
12 3652726
13 7406710
14 14426468
15 27103102
16 49288384
17 87029344
18 149600861
19 250930856
20 411535151
21 661105246
22 1041922558
23 1613307461
24 2457351181
25 3686223670

List of values

[12, 72, 335, 1366, 4948, 16115, 47659, 129463, 326522, 771653, 1722005, 3652726, 7406710, 14426468, 27103102, 49288384, 87029344, 149600861, 250930856, 411535151, 661105246, 1041922558, 1613307461, 2457351181, 3686223670]

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

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