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 A079780 a(n) = largest prime <= n*prime(n). 2
 2, 5, 13, 23, 53, 73, 113, 151, 199, 283, 337, 443, 523, 601, 701, 839, 997, 1097, 1259, 1409, 1531, 1733, 1907, 2131, 2423, 2621, 2777, 2971, 3137, 3389, 3931, 4177, 4519, 4723, 5209, 5431, 5807, 6173, 6491, 6917, 7333, 7591, 8209, 8467, 8863, 9151, 9907 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS a(n) is the largest prime < A079779(n). LINKS Harvey P. Dale, Table of n, a(n) for n = 1..1000 FORMULA a(n) = prime(A057855(n)). - Michel Marcus, Aug 30 2019 MAPLE With exception of first term: seq(prevprime(n*ithprime(n)), n=2..40); MATHEMATICA PrevPrim[n_] := Block[{k = n - 1}, While[ !PrimeQ[k], k-- ]; k]; Table[ Abs[ PrevPrim[ n*Prime[n]]], {n, 1, 50}] Table[Abs[NextPrime[n Prime[n], -1]], {n, 50}] (* Harvey P. Dale, May 25 2012 *) PROG (PARI) for(n=1, 47, print1(precprime(n*prime(n)), ", ")) CROSSREFS Cf. A057855, A079779. Sequence in context: A256491 A106009 A194552 * A178621 A309230 A048871 Adjacent sequences:  A079777 A079778 A079779 * A079781 A079782 A079783 KEYWORD nonn AUTHOR Amarnath Murthy, Feb 03 2003 EXTENSIONS Edited and extended by Robert G. Wilson v, Klaus Brockhaus and Mark Hudson (mrmarkhudson(AT)hotmail.com), Feb 04 2003 STATUS approved

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Last modified December 5 05:39 EST 2021. Contains 349530 sequences. (Running on oeis4.)