A171526 Denominator of (n-th noncomposite/n).

1, 1, 1, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50

Offset

1,4

Comments

Denominator of (A008578(n)/n).

Links

Table of n, a(n) for n=1..50.

Formula

a(1) = a(2) = a(3) = 1, a(n) = n for n >= 4.

Mathematica

Module[{nn=300, c, len}, c=Select[Range[nn], !CompositeQ[#]&]; len=Length[ c]; #[[1]]/#[[2]]&/@Thread[{c, Range[len]}]]//Denominator (* or *) Join[{1, 1, 1}, Range[ 4, 60]] (* Harvey P. Dale, Feb 08 2020 *)

Crossrefs

Cf. A008578.

Sequence in context: A030543 A214084 A114143 * A359740 A171463 A020705

Adjacent sequences: A171523 A171524 A171525 * A171527 A171528 A171529

Keyword

nonn,easy

Author

Jaroslav Krizek, Dec 11 2009

Extensions

Corrected by Jaroslav Krizek, Dec 16 2009

Status

approved