A079444 Number of 3-cycles in range [A014137(2n+2)..A014138(2n+2)] of permutation A057505 (= Donaghey's automorphism M).

1, 3, 7, 15, 33, 65, 133, 267

Offset: 0

Author

Antti Karttunen, Jan 27 2003

Keywords

• nonn
• more

Links

• Antti Karttunen, Illustration of initial terms for trees of sizes 3..11
• Robert Donaghey, Automorphisms on Catalan trees and bracketing, J. Combin. Theory, Series B, 29 (1980), 75-90.

Crossrefs

Cf. A079440, A079442.

Formula

a(n) = A079442(2n+3)/3.