A080783 a(1)=1, a(n)=a(n-1)-1 if n is already in the sequence, a(n)=a(n-1)+5 otherwise.

1, 6, 11, 16, 21, 20, 25, 30, 35, 40, 39, 44, 49, 54, 59, 58, 63, 68, 73, 72, 71, 76, 81, 86, 85, 90, 95, 100, 105, 104, 109, 114, 119, 124, 123, 128, 133, 138, 137, 136, 141, 146, 151, 150, 155, 160, 165, 170, 169, 174, 179, 184, 189, 188, 193, 198

Offset: 1

Author

Benoit Cloitre, Mar 07 2003

Keywords

• nonn

Crossrefs

Cf. A079357, A079354, A080782, A064437.

Programs

Mathematica

lst={1};i=2;Do[If[MemberQ[lst,i],AppendTo[lst,Last[lst]-1], AppendTo[ lst,Last[lst]+5]];i++,{60}];lst (* Harvey P. Dale, Aug 20 2011 *)

Formula

Conjectured to be asymptotic to 3n as n -> infinity.