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A090821 Numbers that are products of two consecutive nonprimes. 0
4, 24, 48, 72, 90, 120, 168, 210, 240, 288, 360, 420, 462, 528, 600, 650, 702, 756, 840, 960, 1056, 1122, 1190, 1260, 1368, 1482, 1560, 1680, 1848, 1980, 2070, 2208, 2352, 2450, 2550, 2652, 2808, 2970, 3080, 3192, 3306, 3480, 3720, 3906, 4032, 4160, 4290 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..47.

EXAMPLE

The nonprimes: 1,4,6,8,9,10,12,14,15 ..., product of consecutive nonprimes: 4,24,48,72,90,...

MATHEMATICA

With[{nonps=Complement[Range[100], Prime[Range[PrimePi[100]]]]}, Times @@@ Partition[nonps, 2, 1]] (* Harvey P. Dale, Jan 16 2012 *)

CROSSREFS

Cf. A018252.

Sequence in context: A066770 A080380 A039935 * A226575 A052645 A191778

Adjacent sequences:  A090818 A090819 A090820 * A090822 A090823 A090824

KEYWORD

easy,nonn

AUTHOR

Felix Tubiana (fat2(AT)columbia.edu), Feb 11 2004

EXTENSIONS

Definition clarified by Harvey P. Dale, Jan 16 2012

STATUS

approved

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Last modified February 16 15:17 EST 2020. Contains 331961 sequences. (Running on oeis4.)