A093986 - cp's OEIS frontend

A093986 a(1) = 1, a(2) = 1, a(n+1) = 2n*a(n) - a(n-1). Symmetrically a(n) = (a(n-1) + a(n+1))/((n-1) + (n+1)).

n	a(n)
1	1
2	1
3	3
4	17
5	133
6	1313
7	15623
8	217409
9	3462921
10	62115169
11	1238840459
12	27192374929
13	651378157837
14	16908639728833
15	472790534249487
16	14166807387755777
17	452865045873935377
18	15383244752326047041
19	553343946037863758099
20	21011686704686496760721

[1, 1, 3, 17, 133, 1313, 15623, 217409, 3462921, 62115169, 1238840459, 27192374929, 651378157837, 16908639728833, 472790534249487, 14166807387755777, 452865045873935377, 15383244752326047041, 553343946037863758099, 21011686704686496760721]

cp's OEIS Frontend

A093986 a(1) = 1, a(2) = 1, a(n+1) = 2n*a(n) - a(n-1). Symmetrically a(n) = (a(n-1) + a(n+1))/((n-1) + (n+1)).

Table of values

List of values