A086170 a(1)=1; a(n)=a(n-1)+1 if n is in the sequence; a(n)=a(n-1)+2 if n and (n-1) are not in the sequence; a(n)=a(n-1)+3 if n is not in the sequence but (n-1) is in the sequence.

1, 4, 6, 7, 10, 11, 12, 15, 17, 18, 19, 20, 23, 25, 26, 29, 30, 31, 32, 33, 36, 38, 39, 42, 43, 44, 47, 49, 50, 51, 52, 53, 54, 57, 59, 60, 63, 64, 65, 68, 70, 71, 72, 73, 76, 78, 79, 82, 83, 84, 85, 86, 87, 88, 91, 93, 94, 97, 98, 99, 102, 104, 105, 106, 107, 110, 112, 113

Offset

1,2

Links

Table of n, a(n) for n=1..68.

Formula

a(n)=phi*n +O(1) where phi=(1+sqrt(5))/2

Crossrefs

Sequence in context: A340833 A340847 A286494 * A123088 A256657 A189085

Adjacent sequences: A086167 A086168 A086169 * A086171 A086172 A086173

Keyword

nonn

Author

Benoit Cloitre, Sep 13 2003

Extensions

Corrected by T. D. Noe, Oct 25 2006

Status

approved