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Search: id:A100557
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| A100557 |
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Smallest prime of the form [prime(n)*prime(n+1)+q]/2 for some integer n and some prime q. |
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+0
1
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| 11, 19, 41, 73, 113, 163, 227, 337, 461, 577, 761, 883, 1013, 1249, 1567, 1801, 2053, 2381, 2593, 2887, 3299, 3697, 4337, 4919, 5231, 5519, 5843, 6173, 7177, 8363, 9007, 9533, 10357, 11251, 11863, 12799, 13613, 14447, 15493, 16223, 17291, 18433, 19013
(list; graph; listen)
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OFFSET
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2,1
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EXAMPLE
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a(2)=19 because 19=(5*7+3)/2;
a(3)=41 because 41=(7*11+5)/2;
a(4)=83 because 73=(11*13+3)/2.
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MATHEMATICA
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f[n_] := Block[{k = 2, q = Prime[n]Prime[n + 1]}, While[p = Prime[k]; !PrimeQ[(q + p)/2], k++ ]; (q + p)/2]; Table[ f[n], {n, 2, 44}] (from Robert G. Wilson v Nov 29 2004)
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CROSSREFS
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Sequence in context: A034303 A140506 A165944 this_sequence A066591 A061246 A068493
Adjacent sequences: A100554 A100555 A100556 this_sequence A100558 A100559 A100560
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KEYWORD
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nonn
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AUTHOR
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Giovanni Teofilatto (g.teofilatto(AT)tiscalinet.it), Nov 28 2004
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EXTENSIONS
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Edited, corrected and extended by Robert G. Wilson v (rgwv(AT)rgwv.com), Nov 29 2004
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