A273020 - cp's OEIS frontend

A273020 a(n) = Sum_{k=0..n} C(n,k)((-1)^n(C(k,n-k)-C(k,n-k-1))+C(n-k,k+1)).

n	a(n)
0	1
1	1
2	3
3	5
4	19
5	39
6	141
7	321
8	1107
9	2675
10	8953
11	22483
12	73789
13	190345
14	616227
15	1621413
16	5196627
17	13882947
18	44152809
19	119385663
20	377379369
21	1030434069
22	3241135527
23	8921880135
24	27948336381
25	77459553549
26	241813226151
27	674100041501
28	2098240353907
29	5878674505303
30	18252025766941

[1, 1, 3, 5, 19, 39, 141, 321, 1107, 2675, 8953, 22483, 73789, 190345, 616227, 1621413, 5196627, 13882947, 44152809, 119385663, 377379369, 1030434069, 3241135527, 8921880135, 27948336381, 77459553549, 241813226151, 674100041501, 2098240353907, 5878674505303, 18252025766941]

cp's OEIS Frontend

A273020 a(n) = Sum_{k=0..n} C(n,k)((-1)^n(C(k,n-k)-C(k,n-k-1))+C(n-k,k+1)).

Table of values

List of values

cp's OEIS Frontend

A273020 a(n) = Sum_{k=0..n} C(n,k)*((-1)^n*(C(k,n-k)-C(k,n-k-1))+C(n-k,k+1)).

Table of values

List of values

A273020 a(n) = Sum_{k=0..n} C(n,k)((-1)^n(C(k,n-k)-C(k,n-k-1))+C(n-k,k+1)).