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%I A007510 M2130
%S A007510 2,23,37,47,53,67,79,83,89,97,113,127,131,157,163,167,173,211,223,233,
%T A007510 251,257,263,277,293,307,317,331,337,353,359,367,373,379,383,389,397,
%U A007510 401,409,439,443,449,457,467,479,487,491,499,503,509,541,547,557,563
%N A007510 Single (or isolated or non-twin) primes.
%C A007510 Primes p such that neither p-2 nor p+2 is prime.
%D A007510 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, 
               Academic Press, 1995 (includes this sequence).
%D A007510 Richard L. Francis, "Isolated Primes", J. Rec. Math., 11 (1978), 17-22.
%H A007510 T. D. Noe, <a href="b007510.txt">Table of n, a(n) for n=1..10000</a>
%H A007510 O. E. Pol, <a href="http://www.polprimos.com">Determinacion geometrica 
               de los numeros primos y perfectos</a>.
%p A007510 with(numtheory): for i from 1 to 150 do p:=ithprime(i): if(not isprime(p+2) 
               and not isprime(p-2)) then printf("%d, ",p) fi od: (Pab Ter)
%t A007510 Transpose[Select[Partition[Prime[Range[100]], 3, 1], #[[2]] - #[[1]] 
               != 2 && #[[3]] - #[[2]] != 2 &]][[2]] - Harvey P. Dale Mar 01 2001
%t A007510 Select[Prime[Range[4,100]],!PrimeQ[ #-2]&&!PrimeQ[ #+2]&] (* Zak Seidov 
               May 07 2007 *)
%o A007510 UBASIC: 10 'primes using counters 20 N=3:print "2 ";:print "3 ";:C=2 
               30 A=3:S=sqrt(N) 40 B=N\A 50 if B*A=N then 55 55 Q=N+2:R=N-2: if 
               Q<>prmdiv(Q) and N=prmdiv(N) and R<>prmdiv(R) then print Q;N;R;"-";
               :stop:else N=N+2:goto 30 60 A=A+2 70 if A<=sqrt(N) then 40:stop 81 
               C=C+1 100 N=N+2:goto 30 - Enoch Haga (Enokh(AT)comcast.net), Oct 
               08 2007
%o A007510 (PARI) forprime(x=2,1000,if(!isprime(x-2)&&!isprime(x+2),print(x))) [From 
               Zak Seidov (zakseidov(AT)yahoo.com), Mar 23 2009]
%Y A007510 Cf. A083370 A124582 A134099 A134100 A134101.
%Y A007510 Sequence in context: A049580 A061448 A115233 this_sequence A117242 A144550 
               A106736
%Y A007510 Adjacent sequences: A007507 A007508 A007509 this_sequence A007511 A007512 
               A007513
%K A007510 nonn,easy,nice
%O A007510 1,1
%A A007510 N. J. A. Sloane (njas(AT)research.att.com), Robert G. Wilson v (rgwv(AT)rgwv.com)
%E A007510 More terms from Pab Ter (pabrlos2(AT)yahoo.com), Nov 11 2005

    
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Last modified December 10 00:48 EST 2009. Contains 170565 sequences.


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