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A159482
Greatest odd prime q < 2*n such that p < q and p prime and p = 2*n - q or 0 if no such prime exists.
1
0, 0, 0, 5, 7, 7, 11, 13, 13, 17, 19, 19, 23, 23, 23, 29, 31, 31, 31, 37, 37, 41, 43, 43, 47, 47, 47, 53, 53, 53, 59, 61, 61, 61, 67, 67, 71, 73, 73, 73, 79, 79, 83, 83, 83, 89, 89, 89, 79, 97, 97, 101, 103, 103, 107, 109, 109, 113, 113, 113, 109, 113, 113, 109, 127, 127
OFFSET
1,4
COMMENTS
q + p = 2*n and p*q = ((q+p)/2)^2 - ((q-p)/2)^2 = n^2 - ((q-p)/2)^2.
Essentially the same as A020482. - R. J. Mathar, Oct 24 2009
CROSSREFS
Sequence in context: A078496 A114521 A258653 * A231935 A216835 A033932
KEYWORD
nonn
AUTHOR
Pierre CAMI, Apr 14 2009
STATUS
approved