A244216 Numbers n that are at least twice the size the largest Catalan number less than or equal to n.

4, 10, 11, 12, 13, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 264

Offset: 1

Author

Antti Karttunen, Jun 23 2014

Keywords

• nonn

Comments

Equally: Numbers k such that if m is the largest Catalan number <= k [= A081290(k)], then k >= 2*m.

Numbers k such that the Greedy Catalan Base representation of k (cf. A014418) starts with digit 2 or 3.

Examples

			4 is present, as the largest Catalan number (A000108(k), here C(k)) less than or equal to 4 is C(2) = 2, and 4 >= 2*2.
5 is not present, as the largest Catalan number <= 5 is C(3) = 5, and 5 < 2*5.
10 is present, as the largest Catalan number <= 10 is C(3) = 5, and 10 >= 2*5.
11 is present, as the largest Catalan number <= 11 is C(3) = 5, and 11 >= 2*5.
27 is not present, as the largest Catalan number <= 27 is C(4) = 14, and 27 < 2*14.
28 is present, as the largest Catalan number <= 28 is C(4) = 14, and 28 >= 2*14.
		

Links

• Antti Karttunen, Table of n, a(n) for n = 1..9878

Crossrefs

Positions of zeros in A244215. Complement of A244217.

Cf. A000108, A014418, A081290.