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A089786 Primes of the form prime(2k) followed by prime(k). 2
73, 197, 7129, 10141, 15161, 19379, 271109, 373157, 593251, 757331, 983431, 997433, 1069463, 1231547, 1361599, 1531661, 1571683, 1627727, 1831811, 2069911, 2161967, 2213977, 24731093, 25311103, 26931193, 27131213, 27911237, 28191259 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000

EXAMPLE

10141 is a term as a concatenation of prime(26)=101 followed by prime(13)=41.

MAPLE

a:=proc(k) local s, m: s:= [op(convert(ithprime(k), base, 10)), op(convert(ithprime(2*k), base, 10))]: m:=add(s[j]*10^(j-1), j=1..nops(s)): if not isprime(m) then RETURN(NULL) else RETURN(m) fi: end; seq(a(k), k=1..250); (C. Ronaldo)

MATHEMATICA

Select[Table[FromDigits[Flatten[IntegerDigits/@{Prime[2n], Prime[n]}]], {n, 250}], PrimeQ] (* Harvey P. Dale, Nov 17 2014 *)

CROSSREFS

Cf. A089782, A089783, A089784, A089785, A089787.

Sequence in context: A088199 A140010 A122723 * A142894 A141909 A296187

Adjacent sequences:  A089783 A089784 A089785 * A089787 A089788 A089789

KEYWORD

base,nonn

AUTHOR

Amarnath Murthy, Nov 24 2003

EXTENSIONS

Corrected and extended by C. Ronaldo (aga_new_ac(AT)hotmail.com), Dec 25 2004

STATUS

approved

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Last modified May 6 17:00 EDT 2021. Contains 343586 sequences. (Running on oeis4.)