There are at least two sequences attributed to B. Recamán. One is the sequence 
formed by taking 
and letting
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(1)
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which can be succinctly defined as "subtract if you can, otherwise add." The first few terms are 1, 3, 6, 2, 7, 13, 20, 12, 21, 11, ... (OEIS A005132), illustrated above.
A view of the first 256 terms as binary bits is shown above.
The terms 1, 2, 3, ... occur at positions 1, 4, 2, 131, 129, 3, 5, ... (OEIS A057167). The high-water marks in this sequence are 1, 4, 131, 99734, 181653, 328002, ... (OEIS A064227), which occur at positions 1, 2, 4, 19, 61, 879, ... (OEIS A064228).
Another sequence defined by Recamán is the sequence obtained by letting 
and defining
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(2)
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(Guy and Nowakowski 1995, Sloane 1999). The first few terms of this sequence are 1, 1, 2, 6, 24, 120, 20, 140, 1120, ... (OEIS A008336).
