A075878 - cp's OEIS frontend

A075878 Sum of coefficients of (x1)^(2i(1))(x2)^(2i(2))(x3)^(2i(3))*(x4)^(2i(4)) for {(i1),(i2),(i3),(i4)}=0,1,2,... : sum(i)=2n in the expansion of (x1+x2+x3+x4)^(2n) where n >= 1.

n	a(n)
1	4
2	40
3	544
4	8320
5	131584
6	2099200
7	33562624
8	536903680
9	8590065664
10	137439477760
11	2199025352704
12	35184380477440
13	562949986975744
14	9007199388958720
15	144115188612726784
16	2305843011361177600
17	36893488156009037824
18	590295810393065390080
19	9444732965876729380864
20	151115727452378402652160
21	2417851639231457372667904

[4, 40, 544, 8320, 131584, 2099200, 33562624, 536903680, 8590065664, 137439477760, 2199025352704, 35184380477440, 562949986975744, 9007199388958720, 144115188612726784, 2305843011361177600, 36893488156009037824, 590295810393065390080, 9444732965876729380864, 151115727452378402652160, 2417851639231457372667904]

cp's OEIS Frontend

A075878 Sum of coefficients of (x1)^(2i(1))(x2)^(2i(2))(x3)^(2i(3))*(x4)^(2i(4)) for {(i1),(i2),(i3),(i4)}=0,1,2,... : sum(i)=2n in the expansion of (x1+x2+x3+x4)^(2n) where n >= 1.

Table of values

List of values

cp's OEIS Frontend

A075878 Sum of coefficients of (x1)^(2i(1))*(x2)^(2i(2))*(x3)^(2i(3))*(x4)^(2i(4)) for {(i1),(i2),(i3),(i4)}=0,1,2,... : sum(i)=2n in the expansion of (x1+x2+x3+x4)^(2n) where n >= 1.

Table of values

List of values

A075878 Sum of coefficients of (x1)^(2i(1))(x2)^(2i(2))(x3)^(2i(3))*(x4)^(2i(4)) for {(i1),(i2),(i3),(i4)}=0,1,2,... : sum(i)=2n in the expansion of (x1+x2+x3+x4)^(2n) where n >= 1.