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A075340 a(1) = 1; a(2n) is the smallest prime == 1 mod (a(2n-1)) and a(2n+1) is the smallest composite number == 1 (mod a(2n)). 1
1, 2, 9, 19, 20, 41, 42, 43, 44, 89, 90, 181, 182, 547, 548, 1097, 1098, 7687, 7688, 15377, 15378, 30757, 30758, 276823, 276824, 553649, 553650, 2768251, 2768252, 8304757, 8304758, 99657097, 99657098, 199314197, 199314198, 3189027169 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
CROSSREFS
Cf. A075341.
Sequence in context: A342619 A342471 A180852 * A031316 A335051 A173663
KEYWORD
nonn
AUTHOR
Amarnath Murthy, Sep 18 2002
EXTENSIONS
More terms from David Wasserman, Jan 16 2005
STATUS
approved

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Last modified March 28 18:04 EDT 2024. Contains 371254 sequences. (Running on oeis4.)