

A117311


Beginning with sequence A096903, choose only those rows such that when a(n) is in factored form all exponents of a(n) are consecutive starting at 1.


0



2, 6, 12, 18, 30, 60, 90, 150, 180, 300, 450, 210, 360, 540, 600, 1350, 1500, 2250, 420, 630, 1050, 1470, 1260, 2100, 2940, 3150, 4410, 7350, 2310, 2520, 3780, 4200, 5880, 9450, 10500, 13230, 15750, 20580, 30870, 36750, 51450, 4620, 6930, 11550, 16170
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OFFSET

1,1


COMMENTS

Included rows can be mapped to permutation groups; e.g.  (12,18) to C2; (60,90,150) and (180,300,450) to C3; (360,540,600,1350,1500,2250) to S3; and (420,630,1050,1470) to C4.


LINKS



EXAMPLE

10 is not a member of a(n) since it is not a term in A096903.
24 is not a member of a(n) since 24 = 2^3 * 3^1 and exponents 1 & 3 are not consecutive.
12, 60 and 180 are included since the exponents are (2,1), (2,1,1) & (2,2,1) respectively.


CROSSREFS



KEYWORD

nonn,tabf


AUTHOR



EXTENSIONS



STATUS

approved



