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A105453
Numbers n such that prime(n) + n*prime(n+1) is prime.
1
2, 14, 16, 20, 24, 30, 40, 44, 48, 72, 76, 84, 96, 120, 122, 160, 168, 182, 214, 230, 254, 266, 270, 280, 288, 292, 294, 330, 338, 360, 390, 428, 490, 496, 512, 540, 544, 546, 552, 560, 576, 578, 582, 644, 654, 656, 660, 714, 726, 740, 746, 750, 758, 762
OFFSET
1,1
MATHEMATICA
bb={}; Do[If[PrimeQ[Prime[n]+n*Prime[n+1]], bb=Append[bb, n]], {n, 2, 400, 2}]; bb
Select[Range[2, 1200], PrimeQ[Prime[#] + # Prime[# + 1]] &] (* Harvey P. Dale, May 02 2012 *)
PROG
(PARI) is(n, p=prime(n))=isprime(p+nextprime(p+1)*n) \\ Charles R Greathouse IV, Jun 13 2017
CROSSREFS
Sequence in context: A194230 A109993 A075041 * A199368 A121716 A194379
KEYWORD
nonn
AUTHOR
Zak Seidov, May 02 2005
EXTENSIONS
More terms from Harvey P. Dale, May 02 2012
STATUS
approved