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A100042 a(n) = prime(n)*2^prime(n). 1
8, 24, 160, 896, 22528, 106496, 2228224, 9961472, 192937984, 15569256448, 66571993088, 5085241278464, 90159953477632, 378231999954944, 6614661952700416, 477381560501272576, 34011184385901985792 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

A lower bound for the 2-color van der Waerden number A005346(prime(n)); see Berlekamp reference. - Charles R Greathouse IV, Jul 13 2008

LINKS

Table of n, a(n) for n=1..17.

E. R. Berlekamp, A construction for partitions which avoid long arithmetic progressions, Canadian Mathematical Bulletin 11 (1968), pp. 409-414.

MAPLE

seq(ithprime(n)*2^ithprime(n), n=1..20);

PROG

(PARI) a(n) = prime(n)*2^prime(n); \\ Michel Marcus, May 14 2017

CROSSREFS

Cf. A034785.

Sequence in context: A092771 A279483 A098070 * A061027 A226962 A221784

Adjacent sequences:  A100039 A100040 A100041 * A100043 A100044 A100045

KEYWORD

nonn

AUTHOR

Jorge Coveiro, Dec 26 2004

STATUS

approved

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Last modified September 21 19:55 EDT 2019. Contains 327279 sequences. (Running on oeis4.)