A344228 - cp's OEIS frontend

A344228 a(n) = binomial(2n,n)(2n+1)/2+nbinomial(2n-2,n)+(n-1)binomial(2*n-2,n+1).

n	a(n)
1	3
2	17
3	84
4	393
5	1778
6	7866
7	34254
8	147433
9	628914
10	2663934
11	11219728
12	47033322
13	196393044
14	817338580
15	3391858530
16	14040986985
17	57998364690
18	239112756630
19	984126777480
20	4044255577230
21	16597080112860
22	68027923573740

[3, 17, 84, 393, 1778, 7866, 34254, 147433, 628914, 2663934, 11219728, 47033322, 196393044, 817338580, 3391858530, 14040986985, 57998364690, 239112756630, 984126777480, 4044255577230, 16597080112860, 68027923573740]

cp's OEIS Frontend

A344228 a(n) = binomial(2n,n)(2n+1)/2+nbinomial(2n-2,n)+(n-1)binomial(2*n-2,n+1).

Table of values

List of values

cp's OEIS Frontend

A344228 a(n) = binomial(2*n,n)*(2*n+1)/2+n*binomial(2*n-2,n)+(n-1)*binomial(2*n-2,n+1).

Table of values

List of values

A344228 a(n) = binomial(2n,n)(2n+1)/2+nbinomial(2n-2,n)+(n-1)binomial(2*n-2,n+1).