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A030459
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Prime p concatenated with next prime is also prime.
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15
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2, 31, 83, 151, 157, 167, 199, 233, 251, 257, 263, 271, 331, 353, 373, 433, 467, 509, 523, 541, 601, 653, 661, 677, 727, 941, 971, 1013, 1033, 1181, 1187, 1201, 1223, 1259, 1367, 1453, 1459, 1657, 1669, 1709, 1741, 1861, 1973, 2069, 2161
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| Terms 157, 257, 263, 541, 1187, 1459, 2179 also belong to A030460. [Carmine Suriano, Jan 27 2011]
All terms, except for the first one, must be either in A185934 or in A185935, i.e., have the same residue (mod 6) as the subsequent prime. [M. F. Hasler, Feb 06 2011]
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LINKS
| M. F. Hasler, Table of n, a(n) for n = 1..4110
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FORMULA
| A030459(n) = A151799( A030460(n)).
A030461(n) = concat(A030459(n),A030460(n)) = A045533( A000720( A030459(n))).
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MATHEMATICA
| Select[Prime[Range[500]], PrimeQ[FromDigits[Join[IntegerDigits[#], IntegerDigits[ NextPrime[#]]]]]&] (* From Harvey P. Dale, June 20 2011 *)
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PROG
| (PARI) o=2; forprime(p=3, 1e4, isprime(eval(Str(o, o=p))) & print1(precprime(p-1)", ")) \\ - M. F. Hasler, Feb 06 2011
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CROSSREFS
| See A030461 for the concatenated primes.
Sequence in context: A175446 A054207 A104095 * A141978 A101254 A107170
Adjacent sequences: A030456 A030457 A030458 * A030460 A030461 A030462
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KEYWORD
| nonn,base
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AUTHOR
| Patrick De Geest (pdg(AT)worldofnumbers.com)
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