A162437 a(1)=1, a(2)=2. Take terms a(n-1) and a(n-2), then convert to binary. Concatenate them, with either binary a(n-1) on the left and a(n-2) on the right, or with a(n-1) on the right and a(n-2) on the left such that the value of the resulting binary number is minimized. a(n) = the decimal equivalent of the resulting binary number.

1, 2, 5, 21, 173, 5549, 1420717, 11638517165, 24407739551034797, 419321772563920711635545517, 15107659029337673520218077770654501397966253

Offset

1,2

Links

Table of n, a(n) for n=1..11.

Example

The binary representation of the first few terms: 1, 10, 101, 10101, 10101101

Mathematica

a[1] = 1; a[2] = 2; a[n_] := Block[{a1 = IntegerDigits[ a[n - 1], 2], a2 = IntegerDigits[ a[n - 2], 2]}, Min[ FromDigits[ Join[a1, a2], 2], FromDigits[ Join[a2, a1], 2]]]; Array[a, 13] (* Robert G. Wilson v, Jul 27 2009 *)

Crossrefs

Cf. A005203, A111061, A162438.

Sequence in context: A176527 A117261 A108021 * A357871 A216756 A007570

Adjacent sequences: A162434 A162435 A162436 * A162438 A162439 A162440

Keyword

base,nonn

Author

Leroy Quet, Jul 03 2009

Extensions

More terms from Robert G. Wilson v, Jul 27 2009

Status

approved