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A087378
Smallest k such that both k-n and k+n are primes and there are no primes between them.
3
2, 4, 9, 26, 93, 144, 205, 120, 1839, 532, 897, 1140, 1681, 2490, 2985, 4312, 5607, 1344, 9569, 30612, 19353, 16162, 15705, 81486, 28253, 31932, 19635, 35644, 82101, 44322, 43361, 34092, 89721, 162176, 134547, 173394, 31433, 404634, 212739
OFFSET
0,1
COMMENTS
For n>0, a(n) = arithmetic mean of the smallest pair of two consecutive primes with a difference 2n.
FORMULA
a(n) = A000230(n)+n. - David Wasserman, May 24 2005
EXAMPLE
a(5) = 144 as 139 and 149 both are prime and all numbers from 140 to 148 are composite.
CROSSREFS
Sequence in context: A307317 A188669 A243568 * A004252 A114957 A002773
KEYWORD
nonn
AUTHOR
Amarnath Murthy, Sep 09 2003
EXTENSIONS
More terms from David Wasserman, May 24 2005
Edited by Franklin T. Adams-Watters, Oct 26 2006
STATUS
approved