A074678 - cp's OEIS frontend

A074678 a(n) = Sum_{j=0..floor(n/2)} (-1)^(j+floor(n/2))*S(2j+q), where S(n) are generalized tribonacci numbers (A001644) and q = (1-(-1)^n)/2.

n	a(n)
0	3
1	1
2	0
3	6
4	11
5	15
6	28
7	56
8	103
9	185
10	340
11	630
12	1159
13	2127
14	3912
15	7200
16	13243
17	24353
18	44792
19	82390
20	151539
21	278719
22	512644
23	942904
24	1734271
25	3189817
26	5866988
27	10791078
28	19847887
29	36505951
30	67144912
31	123498752
32	227149619
33	417793281

[3, 1, 0, 6, 11, 15, 28, 56, 103, 185, 340, 630, 1159, 2127, 3912, 7200, 13243, 24353, 44792, 82390, 151539, 278719, 512644, 942904, 1734271, 3189817, 5866988, 10791078, 19847887, 36505951, 67144912, 123498752, 227149619, 417793281]

cp's OEIS Frontend

A074678 a(n) = Sum_{j=0..floor(n/2)} (-1)^(j+floor(n/2))*S(2j+q), where S(n) are generalized tribonacci numbers (A001644) and q = (1-(-1)^n)/2.

Table of values

List of values