A119400 - cp's OEIS frontend

A119400 a(n) = Sum_{k=0..n} (n!/k!)^2*binomial(n,k).

n	a(n)
0	1
1	2
2	13
3	172
4	3809
5	126526
6	5874517
7	362848088
8	28744087297
9	2839192902874
10	341922922464701
11	49297062811573732
12	8380916229314577313
13	1658770724530766046422
14	378056469777362366873989
15	98286603829297813268996176
16	28907477297195536067142301697

[1, 2, 13, 172, 3809, 126526, 5874517, 362848088, 28744087297, 2839192902874, 341922922464701, 49297062811573732, 8380916229314577313, 1658770724530766046422, 378056469777362366873989, 98286603829297813268996176, 28907477297195536067142301697]

cp's OEIS Frontend

A119400 a(n) = Sum_{k=0..n} (n!/k!)^2*binomial(n,k).

Table of values

List of values