A175073 -id:A175073 - cp's OEIS frontend

A175071 Natural numbers m with result 1 under iterations of {r mod (max prime p < r)} starting at r = m.

1, 3, 4, 6, 8, 10, 11, 12, 14, 16, 17, 18, 20, 22, 23, 24, 26, 27, 29, 30, 32, 34, 35, 37, 38, 40, 41, 42, 44, 46, 47, 48, 50, 51, 53, 54, 56, 57, 59, 60, 62, 64, 65, 67, 68, 70, 71, 72, 74, 76, 77, 79, 80, 82, 83, 84, 86, 87, 89, 90, 92, 93, 95, 97, 98, 100, 101, 102

Offset: 1

Jaroslav Krizek, Jan 23 2010

nonn

Complement of A175072. Union of A175073 and A175074. [From Jaroslav Krizek, Jan 30 2010]

			Iteration procedure for a(6) = 10: 10 mod 7 = 3, 3 mod 2 = 1. Iteration procedure for a(7) = 11: 11 mod 7 = 4, 4 mod 3 = 1.

nn1Q[n_]:=Last[NestWhileList[Mod[#,NextPrime[#,-1]]&,n,#>1&]]!=0; Select[ Range[ 110],nn1Q] (* Harvey P. Dale, May 05 2015 *)

A175074 Nonprimes b with result 1 under iterations of {r mod (max prime p < r)} starting at r = b.

Original entry on oeis.org

1, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 27, 30, 32, 34, 35, 38, 40, 42, 44, 46, 48, 50, 51, 54, 56, 57, 60, 62, 64, 65, 68, 70, 72, 74, 76, 77, 80, 82, 84, 86, 87, 90, 92, 93, 95, 98, 100, 102

Offset: 1

Jaroslav Krizek, Jan 23 2010

nonn

Subsequence of A175071. Union of a(n) and A175073 is A175071.

Union of a(n) and A175073 is A175071. [From Jaroslav Krizek, Jan 30 2010]

			Iteration procedure for a(5) = 10: 10 mod 7 = 3, 3 mod 2 = 1.

np1Q[n_]:=!PrimeQ[n]&&MemberQ[NestWhileList[Mod[#,NextPrime[#,-1]]&,n,#>0&],1]; Select[Range[150],np1Q] (* Harvey P. Dale, Jun 27 2020 *)

cp's OEIS Frontend

A175071 Natural numbers m with result 1 under iterations of {r mod (max prime p < r)} starting at r = m.

Views

Author

Keywords

Comments

Examples

Programs

Mathematica