A083257 a(n) = A071364(n-th nonprime number) = A071364(A018252(n)).

1, 4, 6, 8, 4, 6, 12, 6, 6, 16, 18, 12, 6, 6, 24, 4, 6, 8, 12, 30, 32, 6, 6, 6, 36, 6, 6, 24, 30, 12, 12, 6, 48, 4, 18, 6, 12, 54, 6, 24, 6, 6, 60, 6, 12, 64, 6, 30, 12, 6, 30, 72, 6, 18, 12, 6, 30, 48, 16, 6, 60, 6, 6, 6, 24, 90, 6, 12, 6, 6, 6, 96, 18, 12, 36, 30, 24, 30, 6, 108, 30, 6

Offset

1,2

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Mathematica

f[n_] := Module[{e = FactorInteger[n][[;; , 2]]}, Times @@ (Prime[Range[Length[e]]]^e)]; f[1] = 1; f /@ Select[Range[120], !PrimeQ[#] &] (* Amiram Eldar, Feb 22 2025 *)

Crossrefs

Cf. A007395, A000040, A002808, A018252, A046523, A071364, A083256.

Sequence in context: A021685 A071851 A083256 * A286366 A331059 A201336

Adjacent sequences: A083254 A083255 A083256 * A083258 A083259 A083260

Keyword

nonn,changed

Author

Labos Elemer, May 09 2003

Extensions

Corrected by Ray Chandler, Aug 01 2004

Status

approved