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A065858
m-th composite number c(m) = A002808(m), where m is the n-th prime number: a(n) = A002808(A000040(n)).
9
6, 8, 10, 14, 20, 22, 27, 30, 35, 44, 46, 54, 58, 62, 66, 75, 82, 85, 92, 96, 99, 108, 114, 120, 129, 134, 136, 142, 144, 148, 166, 171, 178, 182, 194, 196, 204, 210, 215, 221, 230, 232, 245, 247, 252, 254, 268, 285, 289, 291, 296, 302, 304, 318, 324, 330, 338
OFFSET
1,1
COMMENTS
Composites (A002808) with prime (A000040) subscripts. a(n) U A175251(n) = A002808(n). Subsequence of A022449 (composites (A002808) with noncomposite (A008578) subscripts), a(n) = A022449(n+1). - Jaroslav Krizek, Mar 14 2010
MATHEMATICA
Composite[n_] := FixedPoint[n + PrimePi[#] + 1 & , n + PrimePi[n] + 1];
a[n_] := Composite[Prime[n]];
Array[a, 100] (* Jean-François Alcover, Jan 26 2018, after Robert G. Wilson v *)
KEYWORD
nonn
AUTHOR
Labos Elemer, Nov 26 2001
STATUS
approved