A025226 - cp's OEIS frontend

A025226 a(n) = a(1)a(n-1) + a(2)a(n-2) + ...+ a(n-1)a(1) for n >= 2. Also a(n) = 3^nC(n-1), where C = A000108 (Catalan numbers).

n	a(n)
1	3
2	9
3	54
4	405
5	3402
6	30618
7	288684
8	2814669
9	28146690
10	287096238
11	2975361012
12	31241290626
13	331638315876
14	3553267670100
15	38375290837080
16	417331287853245
17	4566095267100210

[3, 9, 54, 405, 3402, 30618, 288684, 2814669, 28146690, 287096238, 2975361012, 31241290626, 331638315876, 3553267670100, 38375290837080, 417331287853245, 4566095267100210]

cp's OEIS Frontend

A025226 a(n) = a(1)a(n-1) + a(2)a(n-2) + ...+ a(n-1)a(1) for n >= 2. Also a(n) = 3^nC(n-1), where C = A000108 (Catalan numbers).

Table of values

List of values

cp's OEIS Frontend

A025226 a(n) = a(1)*a(n-1) + a(2)*a(n-2) + ...+ a(n-1)*a(1) for n >= 2. Also a(n) = 3^n*C(n-1), where C = A000108 (Catalan numbers).

Table of values

List of values

A025226 a(n) = a(1)a(n-1) + a(2)a(n-2) + ...+ a(n-1)a(1) for n >= 2. Also a(n) = 3^nC(n-1), where C = A000108 (Catalan numbers).