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 A122072 Greatest prime less than 10n. 6
 7, 19, 29, 37, 47, 59, 67, 79, 89, 97, 109, 113, 127, 139, 149, 157, 167, 179, 181, 199, 199, 211, 229, 239, 241, 257, 269, 277, 283, 293, 307, 317, 317, 337, 349, 359, 367, 379, 389, 397, 409, 419, 421, 439, 449, 457, 467, 479, 487, 499, 509, 509, 523, 523 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS First repeating terms are 199, 317, 509, 523, 619, 839, 887, 1069, 1129, 1129, 1259, 1327, 1327, 1327, 1409, 1459, 1499, 1637, 1669, 1669, 1709, 1759, 1789, 1847, 1889, 1913, 1951. a(n) is also the greatest prime factor among composites (A002808) below 20n. For primes of the form 20n + 1, see A141881. - Lekraj Beedassy, Jan 23 2012 LINKS Charles R Greathouse IV, Table of n, a(n) for n = 1..10000 MATHEMATICA Table[Prime[PrimePi[10 n]], {n, 54}] (* Jayanta Basu, May 24 2013 *) PROG (PARI) a(n)=precprime(10*n) \\ Charles R Greathouse IV, Feb 26 2012 CROSSREFS Sequence in context: A175376 A175366 A117609 * A261338 A109355 A272404 Adjacent sequences:  A122069 A122070 A122071 * A122073 A122074 A122075 KEYWORD nonn,easy AUTHOR Zak Seidov, Oct 16 2006 STATUS approved

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Last modified July 28 09:26 EDT 2021. Contains 346323 sequences. (Running on oeis4.)