A074677 - cp's OEIS frontend

A074677 a(n) = Sum_{i = 0..floor(n/2)} (-1)^(i + floor(n/2)) F(2*i + e), where F = A000045 (Fibonacci numbers) and e = (1-(-1)^n)/2.

n	a(n)
0	0
1	1
2	1
3	1
4	2
5	4
6	6
7	9
8	15
9	25
10	40
11	64
12	104
13	169
14	273
15	441
16	714
17	1156
18	1870
19	3025
20	4895
21	7921
22	12816
23	20736
24	33552
25	54289
26	87841
27	142129
28	229970
29	372100
30	602070
31	974169
32	1576239
33	2550409
34	4126648
35	6677056
36	10803704
37	17480761
38	28284465
39	45765225
40	74049690

[0, 1, 1, 1, 2, 4, 6, 9, 15, 25, 40, 64, 104, 169, 273, 441, 714, 1156, 1870, 3025, 4895, 7921, 12816, 20736, 33552, 54289, 87841, 142129, 229970, 372100, 602070, 974169, 1576239, 2550409, 4126648, 6677056, 10803704, 17480761, 28284465, 45765225, 74049690]

cp's OEIS Frontend

A074677 a(n) = Sum_{i = 0..floor(n/2)} (-1)^(i + floor(n/2)) F(2*i + e), where F = A000045 (Fibonacci numbers) and e = (1-(-1)^n)/2.

Table of values

List of values