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A083562 Beginning of first chain of n consecutive primes whose product + 2 is prime. 1
3, 3, 3, 17, 3, 5, 67, 29, 3, 3, 3, 373, 5, 3, 5, 3, 257, 641, 7, 383, 43, 139, 571, 3967, 2971, 7, 677, 3, 317, 571, 71, 659, 11, 43, 59, 479, 719, 2293, 5, 5237, 1039, 37, 757, 719, 41, 5023, 3, 31, 971, 7, 593, 163, 5003, 1867, 19, 1283, 4549, 17, 4817, 1301 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..500

EXAMPLE

17 is the smallest prime in 17, 19, 23, 29 which is the first chain of four consecutive primes whose product + 2 is prime: 17 * 19 * 23 * 29 + 2 = 215443 (prime). Hence a(4) = 17.

MATHEMATICA

pl=Prime[Range[1000]]; frp[n_] := Module[{pl2=Partition[pl, n, 1]}, First[Select[pl2, PrimeQ[(Times@@#)+2]&][[1]]]]; Table[frp[i], {i, 25}]

CROSSREFS

Sequence in context: A110668 A176248 A290159 * A332860 A106542 A342363

Adjacent sequences:  A083559 A083560 A083561 * A083563 A083564 A083565

KEYWORD

nonn

AUTHOR

Joseph L. Pe, Jun 12 2003

EXTENSIONS

More terms from Amiram Eldar, Sep 29 2019

STATUS

approved

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Last modified July 29 08:05 EDT 2021. Contains 346340 sequences. (Running on oeis4.)