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A056955 Euclid set of class 2 and modulus 3. 1

%I #16 Nov 21 2014 14:35:13

%S 5,8,11,17,23,29,41,47,53,59,71,83,89,101,107,113,131,137,149,167,173,

%T 179,191,197,227,233,239,251,257,263,269,281,293,311,317,347,353,359,

%U 383,389,401,419,431,443,449,461,467,479,491,503,509,521,557,563,569

%N Euclid set of class 2 and modulus 3.

%C For c<m, (m,c)=1, the Euclid(c, m) set is obtained by deleting from the set of numbers c+m*k, for k>0, every term which has a common factor with a smaller term. See Link for more details.

%C Essentially the same as A003627, which drops the 8 for 2. - _Charles R Greathouse IV_, Nov 21 2014

%H Vincenzo Librandi, <a href="/A056955/b056955.txt">Table of n, a(n) for n = 1..1000</a>

%H Andrea Ercolino, <a href="http://www.mondotondo.com/aercolino/goldbach/">XGC - An extension of the Goldbach Conjecture</a>

%e The Euclid(2,3) set is constructed by starting from the set of numbers of the form 2+3*k for k>0, i.e., 5, 8, 11, 14, 17, 20, 23, 26, 29, 32, 35,... and deleting every term which has a common factor with a previous one, like 14, 20, 26, 32, 35,... and so on.

%t eu[c_, m_, n_] := Block[{v, k=1, p=1}, Table[ While[GCD[v = c + m*k, p] > 1, k++]; p *= v; v, {n}]]; eu[2, 3, 55] (* _Giovanni Resta_, Mar 14 2014 *)

%o (PARI) is(n)=n%3==2 && ((isprime(n) && n>2) || n==8) \\ _Charles R Greathouse IV_, Nov 21 2014

%K nonn,easy

%O 1,1

%A Andrea Ercolino (aercolino(AT)yahoo.com)

%E Edited by _Giovanni Resta_, Mar 14 2014

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Last modified April 25 11:39 EDT 2024. Contains 371969 sequences. (Running on oeis4.)