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A079747 Numbers n such that gpf(n-1)<gpf(n)<gpf(n+1), where gpf is the greatest prime factor (A006530). 4
2, 9, 10, 21, 22, 25, 28, 33, 46, 57, 58, 78, 82, 85, 91, 92, 93, 106, 115, 121, 126, 133, 136, 141, 145, 148, 166, 169, 170, 171, 172, 176, 177, 178, 190, 201, 205, 213, 217, 221, 222, 226, 232, 235, 236, 248, 253, 261, 262, 276, 289, 290, 301, 316, 325, 346 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

n such that A079748(n-1) > 1.

LINKS

T. D. Noe, Table of n, a(n) for n=1..1000

FORMULA

a(n) = A071869(n-1) + 1. - T. D. Noe, Nov 26 2007

EXAMPLE

n=25: 25-1=24=3*2^3, 25=5^2 and 25+1=26=13*2, therefore 25 is a term (3<5<13).

CROSSREFS

Cf. A071870, A082417-A082422

Sequence in context: A046975 A304441 A005695 * A191576 A081346 A301872

Adjacent sequences:  A079744 A079745 A079746 * A079748 A079749 A079750

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Jan 10 2003

STATUS

approved

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Last modified September 20 08:05 EDT 2019. Contains 327214 sequences. (Running on oeis4.)