A294730 - OEIS

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A294730

Smallest average >= 6 of a twin prime pair that has exactly 2*n divisors, 0 if no such pair exists.

6, 12, 30, 0, 60, 192, 270, 180, 240, 0, 420, 0, 2112, 1620, 1320, 0, 2340, 786432, 3120, 4800, 15360, 0, 3360, 388962, 724992, 6300, 29760, 0, 12240, 0, 7560, 617472, 47382528, 81648, 21600, 0, 651952128, 995328, 21840, 0, 33600, 0, 138240

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OFFSET

2,1

COMMENTS

It is conjectured that a(n)=0 for prime n with the only exceptions given by n=A181490(k)+1, i.e. a(2)=6, a(3)=12, a(7)=192 and a(19)=786432 are the only currently known exceptions.

LINKS

Table of n, a(n) for n=2..44.

CROSSREFS

Cf. A014574, A068525, A075590, A181490.

Sequence in context: A223346 A109510 A034715 * A079390 A124679 A242949

Adjacent sequences: A294727 A294728 A294729 * A294731 A294732 A294733

KEYWORD

nonn

AUTHOR

Hugo Pfoertner, Nov 08 2017

STATUS

approved