A336578 - cp's OEIS frontend

A336578 a(0) = 1 and a(n) = (1/n) * Sum_{k=1..n} 3^k * binomial(n,k) * binomial(n^2,k-1) for n > 0.

n	a(n)
0	1
1	3
2	21
3	408
4	14799
5	817743
6	61621806
7	5921141502
8	694008501627
9	96176405390961
10	15400332946269903
11	2799678523675400832
12	569877183695866859625
13	128436925725088289658534
14	31756620986815666396814796
15	8548059658831271609064999978
16	2488568825786280454788465874035
17	779186768737628124697943895022101

[1, 3, 21, 408, 14799, 817743, 61621806, 5921141502, 694008501627, 96176405390961, 15400332946269903, 2799678523675400832, 569877183695866859625, 128436925725088289658534, 31756620986815666396814796, 8548059658831271609064999978, 2488568825786280454788465874035, 779186768737628124697943895022101]

cp's OEIS Frontend

A336578 a(0) = 1 and a(n) = (1/n) * Sum_{k=1..n} 3^k * binomial(n,k) * binomial(n^2,k-1) for n > 0.

Table of values

List of values