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A154371 Composites with largest prime factor - smallest prime factor = prime. 0
10, 14, 15, 20, 26, 28, 30, 35, 38, 40, 42, 45, 50, 52, 56, 60, 62, 70, 75, 76, 78, 80, 84, 86, 90, 98, 100, 104, 112, 114, 120, 122, 124, 126, 130, 135, 140, 143, 146, 150, 152, 156, 160, 168, 172, 175, 180, 182, 186, 190, 196, 200, 206, 208, 210, 218, 224, 225 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Duplicate of A119613 - Georg Fischer, Oct 01 2018

LINKS

Table of n, a(n) for n=1..58.

FORMULA

a(n) = A002808(A154370(n)). [From R. J. Mathar, May 05 2010]

EXAMPLE

If 10(composite)=5*2 and 5-2=3(prime), then 10=a(1). If 14(composite)=7*2 and 7-2=5(prime), then 14=a(2). If 15(composite)=5*3 and 5-3=2(prime), then 15=a(3). If 20(composite)=5*2*2 and 5-2=3(prime), 20=a(4), etc.

CROSSREFS

Cf. A000040, A002808.

Sequence in context: A307589 A209800 A119613 * A172509 A036338 A108793

Adjacent sequences:  A154368 A154369 A154370 * A154372 A154373 A154374

KEYWORD

nonn

AUTHOR

Juri-Stepan Gerasimov, Jan 08 2009

EXTENSIONS

Corrected (62 inserted, 133 removed....) by R. J. Mathar, May 05 2010

STATUS

approved

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Last modified October 13 23:56 EDT 2019. Contains 327983 sequences. (Running on oeis4.)