A211067 - cp's OEIS frontend

A211067 Number of 2 X 2 matrices having all terms in {1,...,n} and positive even determinant.

n	a(n)
1	0
2	2
3	13
4	64
5	144
6	362
7	617
8	1200
9	1776
10	2986
11	4101
12	6264
13	8160
14	11714
15	14657
16	20064
17	24464
18	32266
19	38485
20	49320
21	57752
22	72354
23	83585
24	102632
25	117120
26	141578
27	159917
28	190592
29	213496
30	251370
31	279465
32	325704
33	359640
34	415354
35	455973

[0, 2, 13, 64, 144, 362, 617, 1200, 1776, 2986, 4101, 6264, 8160, 11714, 14657, 20064, 24464, 32266, 38485, 49320, 57752, 72354, 83585, 102632, 117120, 141578, 159917, 190592, 213496, 251370, 279465, 325704, 359640, 415354, 455973]

cp's OEIS Frontend

A211067 Number of 2 X 2 matrices having all terms in {1,...,n} and positive even determinant.

Table of values

List of values