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A290333 a(n) is the smallest k which satisfies (j^2 + k)/(j + k^2) = n where j,k are integers and j >= k > 0. 2
1, 3, 2, 4, 11, 27, 3, 12, 5, 31, 2, 95, 3, 495, 36, 7, 69, 8, 10, 231, 17, 8, 5, 80, 4, 3, 68, 47, 5, 11, 12, 23, 2147, 19, 6, 324, 4, 6107, 14, 31, 6585, 803, 12, 164, 14, 11, 5, 252, 75, 351, 8, 160, 17, 1317755, 19, 12, 50, 24, 2040, 5751, 5, 24255, 17, 1024, 521, 26847, 3 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Zhining Yang, Table of n, a(n) for n = 1..300

Zhining Yang, Blog

EXAMPLE

a(5) = 11 since 5 = (27^2 + 11)/(27 + 11^2) and there is no integer k < 11 such that 5 = (j^2 + k)/(j + k^2) with j > k > 1.

PROG

(PARI) for(n=1, 100, for(b=1, 10^8, t=b*(b*n-1); a=floor((n+sqrt(n*n+4*t))/2); if(a*(a-n)==t, print1(b, ", "); break)))

CROSSREFS

Cf. A290332.

Sequence in context: A277743 A296099 A319103 * A137824 A019321 A279261

Adjacent sequences:  A290330 A290331 A290332 * A290334 A290335 A290336

KEYWORD

nonn

AUTHOR

Zhining Yang, Jul 27 2017

STATUS

approved

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Last modified March 26 10:18 EDT 2019. Contains 321491 sequences. (Running on oeis4.)