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A175074 Nonprimes b with result 1 under iterations of {r mod (max prime p < r)} starting at r = b. 2
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

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]

LINKS

Table of n, a(n) for n=1..51.

EXAMPLE

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

MATHEMATICA

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

CROSSREFS

Sequence in context: A330948 A324705 A032583 * A063127 A272651 A103517

Adjacent sequences:  A175071 A175072 A175073 * A175075 A175076 A175077

KEYWORD

nonn

AUTHOR

Jaroslav Krizek, Jan 23 2010

STATUS

approved

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Last modified September 26 21:45 EDT 2020. Contains 337376 sequences. (Running on oeis4.)