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.

A120229 Split-floor-multiplier sequence (SFMS) using multipliers 1/3 and 3. The SFMS using multipliers r and s is here introduced: for every positive integer n and positive real number r, let [rn] abbreviate floor(rn). Then SFMS(r, s), where max {r, s} > 1, is the sequence a defined by a(n)=[rn] if [rn] > 0 and is not already in a and a(n) = [sn] otherwise.

Original entry on oeis.org

3, 6, 1, 12, 15, 2, 21, 24, 27, 30, 33, 4, 39, 42, 5, 48, 51, 54, 57, 60, 7, 66, 69, 8, 75, 78, 9, 84, 87, 10, 93, 96, 11, 102, 105, 108, 111, 114, 13, 120, 123, 14, 129, 132, 135, 138, 141, 16, 147, 150, 17, 156, 159, 18, 165, 168, 19, 174, 177, 20, 183, 186, 189, 192, 195
Offset: 1

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Author

Clark Kimberling, Jun 11 2006

Keywords

Comments

Self-inverse permutation of the natural numbers.

Examples

			a(1) = 1*3 because [1/3] is not positive.
a(2) = 2*3 because [2/3] is not positive.
a(3) = 1 = [3*(1/3)].
a(4) = 4*3 because [4/3] = a(3), not new.
		

References

  • Responses to message "Murthy's sequence A073675" to the seqfan mailing list. The message and responses are dated Feb 02 2006 and relate to generalizations and properties of sequence A073675, which is SFMS(1/2,2).

Crossrefs

Row 3 and column 3 of A059897.

Formula

a(n) = [n/3] if this is positive and new, otherwise a(n)=3n.