A183422 Ordering of the numbers in the tree A183420; complement of A183423.

2, 4, 6, 9, 12, 14, 16, 18, 20, 22, 25, 27, 30, 32, 34, 36, 38, 40, 42, 44, 46, 49, 51, 53, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 76, 78, 81, 83, 85, 87, 90, 92, 94, 96, 100, 102, 104, 106, 110, 112, 114, 116, 119, 121, 123, 125, 127, 130, 132, 134, 136, 138, 141, 144, 146, 148, 150, 153, 156, 158, 160, 162, 165, 169, 171, 173, 175, 178, 182, 184, 186, 188, 191, 194, 196, 198, 200

Offset

1,1

Links

Table of n, a(n) for n=1..87.

Formula

The monotonic ordering of the numbers in the set S generated by these rules: 2 is in S, and if n is in S, then n^2+4*n+2 and n+Floor[1/2+sqrt(n+2)] is in S.

Example

The complementary trees A183420 and A183421 contain initial terms (2,14,4,254,18,34,6,...) and (1,7,3,79,10,23,5,...).  A183422 comes from arranging in increasing order the numbers in the first tree: (2,4,6,9,,12,14,...), these being complementary to the numbers in the second tree.

Mathematica

 nn=200; t={2}; t0=t; While[t=Select[Union[t, (t^2+4t+2), t+Floor[1/2+(t+2)^(1/2)]], #<=nn&]; t0 !=t, t0=t]; t

Crossrefs

Cf. A183423, the complement of A183422.

Sequence in context: A128716 A258934 A225600 * A025057 A189753 A278450

Adjacent sequences: A183419 A183420 A183421 * A183423 A183424 A183425

Keyword

nonn

Author

Clark Kimberling, Jan 04 2011

Status

approved