



1, 0, 7, 7, 8, 9, 10, 10, 10, 10, 12, 12, 12, 12, 13, 13, 13, 14, 15, 16, 16, 16, 16, 16, 17, 17, 17, 18, 19, 19, 19, 20, 20, 20, 21, 22, 22, 22, 22, 23, 23, 24, 24, 24, 24, 25, 25, 25, 25, 25, 26, 26, 27, 28, 28, 28, 30, 30, 30, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 32
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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


FORMULA

a(n) = A050435(n) mod A002808(n).


EXAMPLE

Let c(n) be the nth 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

Cf. A002808, A050435A050439, A065860, A076237A076239.
Sequence in context: A096251 A108186 A024818 * A072520 A187179 A110941
Adjacent sequences: A076233 A076234 A076235 * A076237 A076238 A076239


KEYWORD

nonn


AUTHOR

Labos Elemer, Oct 08 2002


EXTENSIONS

Edited by Michael De Vlieger, Dec 09 2018


STATUS

approved



