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A192599 Let N = pq (p<q) = A006881(n). Then a(n) = | (p^2-q)(q-1)/2 |. 1

%I

%S 1,2,9,8,6,35,54,10,104,54,135,24,209,64,70,90,350,405,72,154,594,190,

%T 740,64,819,280,216,330,989,54,1274,504,22,1595,256,1710,640,714,270,

%U 2079,874,2345,648,56,2484,90,2925,1144,286,3239,1450,3740,1560,216,832,4464,1914,4850,280,320,5049

%N Let N = pq (p<q) = A006881(n). Then a(n) = | (p^2-q)(q-1)/2 |.

%C This is the area of the triangle with vertices (1,p), (p,q), (q,pq).

%C A200050 gives the record values. [Arkadiusz Wesolowski, Apr 18 2012]

%e For p*q=3*5=15, |(3^2 + 5^2 - 5*(3^2 +1))/2| = 8

%K nonn

%O 1,2

%A _J. M. Bergot_, Jul 04 2011

%E Definition simplified by _N. J. A. Sloane_, Jul 10 2011.

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Last modified November 20 14:54 EST 2019. Contains 329337 sequences. (Running on oeis4.)