cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A162438 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 maximized. a(n) = the decimal equivalent of the resulting binary number.

Original entry on oeis.org

1, 2, 6, 26, 218, 7002, 1792858, 14687099738, 30801080592587610, 529158535306496354546309978, 19064945459410035469668296404984822042942298
Offset: 1

Views

Author

Leroy Quet, Jul 03 2009

Keywords

Comments

The difference between A162438(n) - A162437(n): 0, 0, 1, 5, 45, 1453, 372141, 3048582573, ..., . - Robert G. Wilson v, Jul 27 2009

Examples

			The binary representation of the first few terms: 1, 10, 110, 11010, 11011010.
		

Crossrefs

Programs

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

Extensions

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