A076236 a(n) = A050435(n) mod A002808(n).

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

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 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

Cf. A002808, A050435-A050439, A065860, A076237-A076239.

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