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 A239974 Primes which are a concatenation of prime(k+4), prime(k+2) and prime(k) for some k. 1
 1373, 433729, 615343, 797161, 837367, 897971, 149137127, 193181173, 227211197, 337317311, 367353347, 401389379, 443433421, 557541521, 577569557, 587571563, 757743733, 811797773, 823811797, 10191009991, 10211013997, 116311511123, 120111871171, 130713011291 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS All the terms in the sequence are primes which are a reverse concatenation of prime(k), prime(k+2) and prime(k+4) for some k. LINKS K. D. Bajpai, Table of n, a(n) for n = 1..3742 EXAMPLE 1373 is a prime and appears in the sequence because it is the concatenation of prime(2+4), prime(2+2) and prime(2). 433729 is a prime and appears in the sequence because it is the concatenation of prime(10+4), prime(10+2) and prime(10). MAPLE with(StringTools): KD := proc() local a, b, d, e; a:=ithprime(n+4); b:=ithprime(n+2); d:=ithprime(n); e:= parse(cat(a, b, d)); if isprime(e) then RETURN (e); fi; end: seq(KD(), n=1..500); MATHEMATICA Select[Table[FromDigits[Flatten[{IntegerDigits[Prime[n+4]], IntegerDigits[Prime[n+2]], IntegerDigits[Prime[n]]}]], {n, 1, 500}], PrimeQ] CROSSREFS Cf. A000040, A030461, A030469, A030473, A086040, A086041, A239789. Sequence in context: A179915 A168167 A069490 * A258964 A349235 A045131 Adjacent sequences: A239971 A239972 A239973 * A239975 A239976 A239977 KEYWORD nonn,base AUTHOR K. D. Bajpai, Mar 30 2014 STATUS approved

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Last modified May 27 18:57 EDT 2024. Contains 372880 sequences. (Running on oeis4.)