A387401 - cp's OEIS frontend

A387401 a(n) = Sum_{k=0..n} (1-i)^k * (1+i)^(n-k) * binomial(n+1,k) * binomial(n+1,n-k), where i is the imaginary unit.

n	a(n)
0	1
1	4
2	18
3	80
4	360
5	1632
6	7448
7	34176
8	157536
9	728960
10	3384128
11	15754752
12	73525504
13	343870464
14	1611288960
15	7562801152
16	35550504448
17	167339022336
18	788643765248
19	3720901222400
20	17573439614976
21	83074892775424
22	393056192851968
23	1861155016212480
24	8819174122700800
25	41818448615636992

[1, 4, 18, 80, 360, 1632, 7448, 34176, 157536, 728960, 3384128, 15754752, 73525504, 343870464, 1611288960, 7562801152, 35550504448, 167339022336, 788643765248, 3720901222400, 17573439614976, 83074892775424, 393056192851968, 1861155016212480, 8819174122700800, 41818448615636992]

cp's OEIS Frontend

A387401 a(n) = Sum_{k=0..n} (1-i)^k * (1+i)^(n-k) * binomial(n+1,k) * binomial(n+1,n-k), where i is the imaginary unit.

Table of values

List of values