A057646 - cp's OEIS frontend

A057646 a(n) is the number of trinomials x^n + x^k + 1 that are irreducible over GF(2) for some k with n > k > 0.

n	a(n)
2	1
3	2
4	2
5	2
6	3
7	4
8	0
9	4
10	2
11	2
12	4
13	0
14	2
15	6
16	0
17	6
18	5
19	0
20	4
21	4
22	2
23	4
24	0
25	4
26	0
27	0
28	8
29	2
30	4
31	8
32	0
33	4
34	2
35	2
36	6
37	0
38	0
39	6
40	0
41	4
42	2
43	0
44	2
45	0
46	2
47	8
48	0
49	8
50	0
51	0
52	8
53	0
54	5
55	4
56	0
57	8
58	2
59	0
60	12
61	0
62	2
63	10
64	0
65	4
66	2
67	0
68	4
69	0
70	0
71	10
72	0
73	6
74	2
75	0
76	2
77	0
78	0
79	4
80	0
81	6
82	0
83	0
84	14
85	0
86	2
87	2
88	0
89	2
90	2
91	0
92	2
93	2
94	2
95	4
96	0
97	8
98	4
99	0
100	10

[1, 2, 2, 2, 3, 4, 0, 4, 2, 2, 4, 0, 2, 6, 0, 6, 5, 0, 4, 4, 2, 4, 0, 4, 0, 0, 8, 2, 4, 8, 0, 4, 2, 2, 6, 0, 0, 6, 0, 4, 2, 0, 2, 0, 2, 8, 0, 8, 0, 0, 8, 0, 5, 4, 0, 8, 2, 0, 12, 0, 2, 10, 0, 4, 2, 0, 4, 0, 0, 10, 0, 6, 2, 0, 2, 0, 0, 4, 0, 6, 0, 0, 14, 0, 2, 2, 0, 2, 2, 0, 2, 2, 2, 4, 0, 8, 4, 0, 10]

cp's OEIS Frontend

A057646 a(n) is the number of trinomials x^n + x^k + 1 that are irreducible over GF(2) for some k with n > k > 0.

Table of values

List of values

n	a(n)
2	1
3	2
4	2
5	2
6	3
7	4
8	0
9	4
10	2
11	2
12	4
13	0
14	2
15	6
16	0
17	6
18	5
19	0
20	4
21	4
22	2
23	4
24	0
25	4
26	0
27	0
28	8
29	2
30	4
31	8
32	0
33	4
34	2
35	2
36	6
37	0
38	0
39	6
40	0
41	4
42	2
43	0
44	2
45	0
46	2
47	8
48	0
49	8
50	0
51	0
52	8
53	0
54	5
55	4
56	0
57	8
58	2
59	0
60	12
61	0
62	2
63	10
64	0
65	4
66	2
67	0
68	4
69	0
70	0
71	10
72	0
73	6
74	2
75	0
76	2
77	0
78	0
79	4
80	0
81	6
82	0
83	0
84	14
85	0
86	2
87	2
88	0
89	2
90	2
91	0
92	2
93	2
94	2
95	4
96	0
97	8
98	4
99	0
100	10

n	a(n)
2	1
3	2
4	2
5	2
6	3
7	4
8	0
9	4
10	2
11	2
12	4
13	0
14	2
15	6
16	0
17	6
18	5
19	0
20	4
21	4
22	2
23	4
24	0
25	4
26	0
27	0
28	8
29	2
30	4
31	8
32	0
33	4
34	2
35	2
36	6
37	0
38	0
39	6
40	0
41	4
42	2
43	0
44	2
45	0
46	2
47	8
48	0
49	8
50	0
51	0
52	8
53	0
54	5
55	4
56	0
57	8
58	2
59	0
60	12
61	0
62	2
63	10
64	0
65	4
66	2
67	0
68	4
69	0
70	0
71	10
72	0
73	6
74	2
75	0
76	2
77	0
78	0
79	4
80	0
81	6
82	0
83	0
84	14
85	0
86	2
87	2
88	0
89	2
90	2
91	0
92	2
93	2
94	2
95	4
96	0
97	8
98	4
99	0
100	10

n	a(n)
2	1
3	2
4	2
5	2
6	3
7	4
8	0
9	4
10	2
11	2
12	4
13	0
14	2
15	6
16	0
17	6
18	5
19	0
20	4
21	4
22	2
23	4
24	0
25	4
26	0
27	0
28	8
29	2
30	4
31	8
32	0
33	4
34	2
35	2
36	6
37	0
38	0
39	6
40	0
41	4
42	2
43	0
44	2
45	0
46	2
47	8
48	0
49	8
50	0
51	0
52	8
53	0
54	5
55	4
56	0
57	8
58	2
59	0
60	12
61	0
62	2
63	10
64	0
65	4
66	2
67	0
68	4
69	0
70	0
71	10
72	0
73	6
74	2
75	0
76	2
77	0
78	0
79	4
80	0
81	6
82	0
83	0
84	14
85	0
86	2
87	2
88	0
89	2
90	2
91	0
92	2
93	2
94	2
95	4
96	0
97	8
98	4
99	0
100	10