A121537 If n appears then 2n, 3n and 4n do not.

1, 5, 6, 7, 8, 9, 11, 13, 17, 19, 23, 25, 29, 30, 31, 35, 37, 40, 41, 42, 43, 45, 47, 48, 49, 53, 54, 55, 56, 59, 61, 63, 64, 65, 66, 67, 71, 72, 73, 77, 78, 79, 81, 83, 85, 88, 89, 91, 95, 97, 99, 101, 102, 103, 104, 107, 109, 113, 114, 115, 117, 119, 121, 125, 127, 131

Offset

1,2

Comments

A003159 If n appears then 2n does not. A036668 If n appears then 2n and 3n do not.

Links

Table of n, a(n) for n=1..66.

Mathematica

s={1}; Do[If[FreeQ[s, n/2]&&FreeQ[s, n/3]&&FreeQ[s, n/4], AppendTo[s, n]], {n, 2, 150}]; s

Crossrefs

Cf. A003159, A036668.

Sequence in context: A138469 A089362 A333532 * A285219 A047577 A293481

Adjacent sequences: A121534 A121535 A121536 * A121538 A121539 A121540

Keyword

nonn

Author

Zak Seidov, Aug 06 2006

Status

approved