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Nearest neighbors of primes.
11

%I #18 Jan 29 2017 07:22:01

%S 1,2,3,4,6,8,10,12,14,16,18,20,22,24,28,30,32,36,38,40,42,44,46,48,52,

%T 54,58,60,62,66,68,70,72,74,78,80,82,84,88,90,96,98,100,102,104,106,

%U 108,110,112,114,126,128,130,132,136,138,140,148,150,152,156,158,162

%N Nearest neighbors of primes.

%H Seiichi Manyama, <a href="/A045718/b045718.txt">Table of n, a(n) for n = 0..10000</a>

%e p=7 contributes 6 and 8 to the list.

%t Union[ Table[ Prime[ i ]-1, {i, 1, 100} ]~Join~Table[ Prime[ i ]+1, {i, 1, 100} ] ]

%t Union[Flatten[Table[n+{1,-1},{n,Prime[Range[50]]}]]] (* _Harvey P. Dale_, Oct 18 2015 *)

%o (PARI) isA045718(n) = isprime(n-1)||isprime(n+1) \\ _Michael B. Porter_, Feb 02 2010

%Y Cf. A000040.

%K nonn,easy

%O 0,2

%A _Felice Russo_

%E Corrected and extended by _Erich Friedman_