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 A126992 a(n) is the largest prime smaller than sqrt(prime(n)*prime(n+6)). 2
 5, 7, 7, 13, 17, 19, 23, 23, 31, 37, 41, 47, 47, 53, 53, 61, 67, 73, 79, 83, 83, 89, 89, 97, 109, 113, 113, 113, 127, 127, 139, 139, 151, 151, 163, 163, 173, 173, 181, 181, 193, 199, 199, 199, 211, 211, 223, 233, 241, 241, 241, 251, 257, 263, 269 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Robert Israel, Table of n, a(n) for n = 1..10000 MAPLE f:= n -> prevprime(ceil(sqrt(ithprime(n)*ithprime(n+6)))): map(f, [\$1..100]); # Robert Israel, Jun 21 2018 MATHEMATICA Table[Prime[PrimePi[Sqrt[Prime[n]*Prime[n + 6]]]], {n, 1, 55}] Table[NextPrime[Sqrt[Prime[n]Prime[n+6]], -1], {n, 60}] (* Harvey P. Dale, Jul 03 2019 *) CROSSREFS Sequence in context: A144186 A246458 A153979 * A028316 A019163 A228970 Adjacent sequences:  A126989 A126990 A126991 * A126993 A126994 A126995 KEYWORD nonn AUTHOR Artur Jasinski, Jan 01 2007 EXTENSIONS Edited by Stefan Steinerberger, Jul 31 2007 STATUS approved

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Last modified December 15 17:03 EST 2019. Contains 330000 sequences. (Running on oeis4.)