a(n) is the smallest nonnegative integer k where exactly n pairs of positive integers (x, y) exist such that x^2 + 19*y^2 = k.

A374161

a(n) is the smallest nonnegative integer k where exactly n pairs of positive integers (x, y) exist such that x^2 + 19*y^2 = k.

Terms

    a(0) =0a(1) =20a(2) =140a(3) =700a(4) =1540a(5) =17500a(6) =7700a(7) =122500a(8) =26180a(9) =53900a(10) =192500a(11) =7035875a(12) =130900a(13) =592900a(14) =4812500a(15) =1347500a(16) =602140a(17) =150062500a(18) =916300

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