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A215808
Primes of the form 2*prime(k) - prime(k+1).
3
3, 3, 17, 41, 47, 67, 151, 167, 199, 227, 251, 257, 347, 367, 557, 587, 601, 607, 641, 647, 727, 941, 971, 1051, 1091, 1097, 1117, 1181, 1217, 1277, 1361, 1427, 1447, 1447, 1487, 1487, 1499, 1607, 1697, 1741, 1747, 1741, 1777, 1877, 1901, 2087, 2143, 2281
OFFSET
1,1
COMMENTS
Corresponding values of k: 3, 4, 9, 15, 16, 21, 37, 40, 47, 51, 55, 56, 71, 74, 103 (A216075).
EXAMPLE
k=3: 2*5-7=3, k=4: 2*7-11=3, k=9: 2*23-29=17.
MATHEMATICA
pr=Prime[Range[1000]]; s=Select[2*Most[pr]-Rest[pr], PrimeQ]
Select[2#[[1]]-#[[2]]&/@Partition[Prime[Range[500]], 2, 1], PrimeQ] (* Harvey P. Dale, Feb 25 2017 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Zak Seidov, Sep 06 2012
STATUS
approved