A074381 - cp's OEIS frontend

A074381 (p-1)/2 mod 2, where p is the n-th prime for which p+2 is also prime; i.e., a(n)=0 if p==1 (mod 4), a(n)=1 if p==3 (mod 4).

n	a(n)
1	1
2	0
3	1
4	0
5	0
6	0
7	1
8	1
9	0
10	1
11	0
12	0
13	1
14	1
15	0
16	1
17	1
18	0
19	0
20	1
21	1
22	1
23	1
24	0
25	0
26	0
27	1
28	0
29	0
30	1
31	0
32	0
33	1
34	0
35	0
36	1
37	1
38	0
39	0
40	1
41	1
42	0
43	0
44	0
45	0
46	1
47	1
48	1
49	0
50	1
51	1
52	1
53	1
54	0
55	0
56	1
57	1
58	0
59	1
60	0
61	0
62	1
63	0
64	1
65	1
66	0
67	0
68	0
69	1
70	0
71	1
72	0
73	0
74	1
75	0
76	1
77	1
78	0
79	0
80	0
81	0
82	1
83	1
84	1
85	1
86	0
87	1
88	0
89	1
90	1
91	0
92	0
93	1
94	1
95	1
96	0
97	0
98	1
99	1
100	0
101	1
102	0
103	0
104	0
105	1

[1, 0, 1, 0, 0, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 1, 1, 0, 0, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 0, 0, 1, 1, 1, 0, 1, 1, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 0, 0, 1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 1, 0, 1, 1, 0, 0, 1, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 0, 1]

cp's OEIS Frontend

A074381 (p-1)/2 mod 2, where p is the n-th prime for which p+2 is also prime; i.e., a(n)=0 if p==1 (mod 4), a(n)=1 if p==3 (mod 4).

Table of values

List of values

n	a(n)
1	1
2	0
3	1
4	0
5	0
6	0
7	1
8	1
9	0
10	1
11	0
12	0
13	1
14	1
15	0
16	1
17	1
18	0
19	0
20	1
21	1
22	1
23	1
24	0
25	0
26	0
27	1
28	0
29	0
30	1
31	0
32	0
33	1
34	0
35	0
36	1
37	1
38	0
39	0
40	1
41	1
42	0
43	0
44	0
45	0
46	1
47	1
48	1
49	0
50	1
51	1
52	1
53	1
54	0
55	0
56	1
57	1
58	0
59	1
60	0
61	0
62	1
63	0
64	1
65	1
66	0
67	0
68	0
69	1
70	0
71	1
72	0
73	0
74	1
75	0
76	1
77	1
78	0
79	0
80	0
81	0
82	1
83	1
84	1
85	1
86	0
87	1
88	0
89	1
90	1
91	0
92	0
93	1
94	1
95	1
96	0
97	0
98	1
99	1
100	0
101	1
102	0
103	0
104	0
105	1

n	a(n)
1	1
2	0
3	1
4	0
5	0
6	0
7	1
8	1
9	0
10	1
11	0
12	0
13	1
14	1
15	0
16	1
17	1
18	0
19	0
20	1
21	1
22	1
23	1
24	0
25	0
26	0
27	1
28	0
29	0
30	1
31	0
32	0
33	1
34	0
35	0
36	1
37	1
38	0
39	0
40	1
41	1
42	0
43	0
44	0
45	0
46	1
47	1
48	1
49	0
50	1
51	1
52	1
53	1
54	0
55	0
56	1
57	1
58	0
59	1
60	0
61	0
62	1
63	0
64	1
65	1
66	0
67	0
68	0
69	1
70	0
71	1
72	0
73	0
74	1
75	0
76	1
77	1
78	0
79	0
80	0
81	0
82	1
83	1
84	1
85	1
86	0
87	1
88	0
89	1
90	1
91	0
92	0
93	1
94	1
95	1
96	0
97	0
98	1
99	1
100	0
101	1
102	0
103	0
104	0
105	1

n	a(n)
1	1
2	0
3	1
4	0
5	0
6	0
7	1
8	1
9	0
10	1
11	0
12	0
13	1
14	1
15	0
16	1
17	1
18	0
19	0
20	1
21	1
22	1
23	1
24	0
25	0
26	0
27	1
28	0
29	0
30	1
31	0
32	0
33	1
34	0
35	0
36	1
37	1
38	0
39	0
40	1
41	1
42	0
43	0
44	0
45	0
46	1
47	1
48	1
49	0
50	1
51	1
52	1
53	1
54	0
55	0
56	1
57	1
58	0
59	1
60	0
61	0
62	1
63	0
64	1
65	1
66	0
67	0
68	0
69	1
70	0
71	1
72	0
73	0
74	1
75	0
76	1
77	1
78	0
79	0
80	0
81	0
82	1
83	1
84	1
85	1
86	0
87	1
88	0
89	1
90	1
91	0
92	0
93	1
94	1
95	1
96	0
97	0
98	1
99	1
100	0
101	1
102	0
103	0
104	0
105	1