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A087394 Prime(prime(n)) when prime(prime(n)) and n are twin primes. 1
11, 31, 59, 179, 599, 1063, 1153, 1787, 2381, 4091, 4273, 5869, 6661, 9461, 9859, 14867, 15641, 17987, 20773, 20899, 27689, 30557, 39239, 43651, 43889, 61979, 63391, 66749, 66851, 68821, 84347, 96797, 104471, 111271, 132949, 146989, 157771 (list; graph; refs; listen; history; text; internal format)
OFFSET

3,1

LINKS

Harvey P. Dale, Table of n, a(n) for n = 3..1000

EXAMPLE

prime(103) = 563. prime(563) = 4091. 103 and 4091 are twin primes.

MATHEMATICA

Select[Prime[Prime[#]]&/@Union[Flatten[Select[Partition[Prime[Range[400]], 2, 1], #[[2]] - #[[1]]==2&]]], AnyTrue[#+{2, -2}, PrimeQ]&] (* The program uses the AnyTrue function from Mathematica version 10 *) (* Harvey P. Dale, Mar 21 2015 *)

PROG

(PARI) twips(n) = { c1=0; c2=0; forprime(x=3, n, if(isprime(x+2), c1++); x1=prime(prime(x)); if(isprime(x-2) || isprime(x+2), if(isprime(x1-2) || isprime(x1+2), print1(x1", "); c2++; ) ) ); print(); print(c2/c1+.0) }

CROSSREFS

Sequence in context: A226922 A031372 A028877 * A196117 A040162 A113747

Adjacent sequences:  A087391 A087392 A087393 * A087395 A087396 A087397

KEYWORD

easy,nonn

AUTHOR

Cino Hilliard, Oct 21 2003

STATUS

approved

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Last modified September 26 05:53 EDT 2022. Contains 356986 sequences. (Running on oeis4.)