OFFSET

1,3

COMMENTS

Original name: Remainder when 2nd order composite, A050435(n), is divided by first order composite, A002808(n). - Michael De Vlieger, Dec 09 2018

LINKS

Michael De Vlieger, Table of n, a(n) for n = 1..10000

EXAMPLE

Let c(n) be the n-th composite number. a(1) = 1 since c(c(1)) mod c(1) = c(4) mod 4 = 9 mod 4 = 1. a(2) = 0 since c(c(2)) mod c(2) = c(6) mod 6 = 12 mod 6 = 0. - Michael De Vlieger, Dec 09 2018

MATHEMATICA

c[n_] := FixedPoint[n + PrimePi[#] + 1 &, n + PrimePi[n] + 1]; Array[Mod[c@ c@ #, c@ #] &, 71] (* Michael De Vlieger, Dec 09 2018, after Robert G. Wilson v at A002808 *)

CROSSREFS

KEYWORD

nonn

AUTHOR

Labos Elemer, Oct 08 2002

EXTENSIONS

Edited by Michael De Vlieger, Dec 09 2018

STATUS

approved