A144075 Duplicate of A008621.

1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 6, 6, 6, 6, 7, 7, 7, 7, 8, 8, 8, 8, 9, 9, 9, 9, 10, 10, 10, 10, 11, 11, 11, 11, 12, 12, 12, 12, 13, 13, 13, 13, 14, 14, 14, 14, 15, 15, 15, 15, 16, 16, 16, 16, 17, 17, 17, 17, 18, 18, 18, 18, 19, 19, 19, 19, 20, 20, 20, 20, 21, 21

Offset

1,4

Links

Table of n, a(n) for n=1..81.

Eric Weisstein's World of Mathematics, Graph Thickness

Formula

G.f.: x(1+x^3-x^4)/((1-x)^2(1+x)(1+x^2)). - R. J. Mathar, Sep 12 2008

Mathematica

Ceiling[(n+1)/4]

Crossrefs

Cf. A002265, A128929.

Sequence in context: A242601 A110655 A008621 * A128929 A257839 A075245

Adjacent sequences: A144072 A144073 A144074 * A144076 A144077 A144078

Keyword

dead

Author

Eric W. Weisstein, Sep 09 2008

Status

approved