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A123200
Numbers k such that 1000000*k-1 and 1000000*k+1 are twin primes.
1
24, 30, 198, 345, 348, 432, 438, 471, 492, 609, 669, 774, 777, 858, 864, 1032, 1083, 1125, 1218, 1395, 1536, 1824, 1914, 1929, 2088, 2139, 2301, 2334, 2376, 2418, 2448, 2460, 2544, 2763, 2832, 2970, 3021, 3297, 3369, 3384, 3495, 3528, 3540, 3633, 3777
OFFSET
1,1
LINKS
EXAMPLE
a(6) = 432 because 431999999 and 432000001 are primes.
MAPLE
a:=proc(n) if isprime(10^6*n-1)=true and isprime(10^6*n+1)=true then n else fi end: seq(a(n), n=1..4500); # Emeric Deutsch, Nov 16 2006
MATHEMATICA
Select[Range[3800], AllTrue[#*10^6+{1, -1}, PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Nov 13 2017 *)
CROSSREFS
KEYWORD
easy,nonn,less
AUTHOR
Jonathan Vos Post, Nov 05 2006
EXTENSIONS
More terms from Emeric Deutsch, Nov 16 2006
STATUS
approved