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Search: id:A126334
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| A126334 |
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a(n) = p, the lesser of twin primes (p,q=p+2) such that p*q-p-q and p*q+p+q are primes. |
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2
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| 3, 5, 17681, 21377, 21587, 33599, 41201, 41411, 70139, 74759, 84629, 109619, 114197, 130619, 155861, 160481, 174467, 219407, 222977, 223439, 230999, 235787, 243431, 284129, 285641, 287279, 300929, 325079, 373211, 386987, 389297, 397151
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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Or, primes p such that p+2, p^2-2 and 2 + 4*p + p^2 are primes. Intersection of A128550 and A128551.
The number of such p's <= 10^n: 2, 2, 2, 2, 11, 56, 320, 1772, ..., . - Robert G. Wilson v (rgwv(AT)rgwv.com), Mar 11 2007
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MATHEMATICA
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fQ[n_] := Block[{p = Prime[n], q = Prime[n + 1]}, p + 2 == q && PrimeQ[p*q - p - q] && PrimeQ[p*q + p + q]]; lst = {}; Do[ If[ fQ@n == True, AppendTo[lst, Prime@n]; Print@ Prime@n], {n, 39055}] - Robert G. Wilson v (rgwv(AT)rgwv.com), Mar 11 2007
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CROSSREFS
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Cf. A096342, A126148, A128547, A128548, A128550, A128551.
Sequence in context: A062655 A090807 A138154 this_sequence A068635 A071105 A104613
Adjacent sequences: A126331 A126332 A126333 this_sequence A126335 A126336 A126337
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KEYWORD
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nonn
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AUTHOR
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Zak Seidov (zakseidov(AT)gmail.com), Mar 10 2007
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EXTENSIONS
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More terms from Robert G. Wilson v (rgwv(AT)rgwv.com), Mar 11 2007
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