A056136 - OEIS

A056136

Largest positive integer whose harmonic mean with another positive integer is n.

1, 2, 6, 6, 15, 12, 28, 20, 45, 30, 66, 42, 91, 56, 120, 72, 153, 90, 190, 110, 231, 132, 276, 156, 325, 182, 378, 210, 435, 240, 496, 272, 561, 306, 630, 342, 703, 380, 780, 420, 861, 462, 946, 506, 1035, 552, 1128, 600, 1225, 650, 1326, 702, 1431, 756, 1540

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OFFSET

1,2

LINKS

Table of n, a(n) for n=1..55.

FORMULA

a(n) =1/(2/n-1/floor[n/2+1]) =n*A008619(n)/(2*A008619(n)-n) =(n/2)*A029578(n+2)

CROSSREFS

Cf. A008619 for the smallest integer whose harmonic mean with another integer is n (i.e. harmonic mean of A008619 and a(n) is n).

Sequence in context: A367072 A251548 A316785 * A349288 A098571 A194120

Adjacent sequences: A056133 A056134 A056135 * A056137 A056138 A056139

KEYWORD

nonn

AUTHOR

Henry Bottomley, Jun 13 2000

STATUS

approved