A111654 n appears n-th composite number times.

1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9

Offset: 1

Author

Jonathan Vos Post, Aug 12 2005

Keywords

• easy
• less
• nonn

Comments

n appears A002808(n) times.

Crossrefs

Cf. A002808, A111653, A111655.

Programs

Mathematica

Module[{nn=20,comps,len},comps=Select[Range[nn],CompositeQ];len=Length[ comps];Flatten[Table[#[[1]],{#[[2]]}]&/@Thread[{Range[len],comps}]]] (* Harvey P. Dale, Aug 17 2014 *)