A005130 - cp's OEIS frontend

A005130 Robbins numbers: a(n) = Product_{k=0..n-1} (3k+1)!/(n+k)!; also the number of descending plane partitions whose parts do not exceed n; also the number of n X n alternating sign matrices (ASM's).

n	a(n)
0	1
1	1
2	2
3	7
4	42
5	429
6	7436
7	218348
8	10850216
9	911835460
10	129534272700
11	31095744852375
12	12611311859677500
13	8639383518297652500
14	9995541355448167482000
15	19529076234661277104897200
16	64427185703425689356896743840
17	358869201916137601447486156417296

[1, 1, 2, 7, 42, 429, 7436, 218348, 10850216, 911835460, 129534272700, 31095744852375, 12611311859677500, 8639383518297652500, 9995541355448167482000, 19529076234661277104897200, 64427185703425689356896743840, 358869201916137601447486156417296]

cp's OEIS Frontend

A005130 Robbins numbers: a(n) = Product_{k=0..n-1} (3k+1)!/(n+k)!; also the number of descending plane partitions whose parts do not exceed n; also the number of n X n alternating sign matrices (ASM's).

Table of values

List of values