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A257841 z-value of the lexicographically first solution (x,y,z) of 4/n = 1/x + 1/y + 1/z with 0 < x < y < z all integers, or 0 if there is no such solution. Corresponding x and y values are in A257839 and A257840. 5
0, 0, 12, 6, 20, 42, 210, 42, 90, 240, 1122, 156, 468, 812, 3660, 420, 510, 2070, 9120, 930, 1806, 4422, 19182, 1806, 2100, 8372, 35910, 3192, 9048, 14520, 61752, 5256, 9900, 23562, 99540, 8190, 22940, 36290, 152490, 12210, 6314, 53592, 224202, 17556, 32580, 76452, 318660, 24492, 9702, 105950, 440232, 33306, 92008, 143262, 593670, 44310, 81510, 189660, 784110, 57840 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

See A073101 for more details.

This differs from A075247 starting with a(89)=61410 vs A075247(89)=108936, corresponding to the representations 4/89 = 1/23 + 1/690 + 1/61410 = 1/24 + 1/306 + 1/108936.

LINKS

M. F. Hasler, Table of n, a(n) for n = 1..1000

PROG

(PARI) A257841(n)=for(c=n\4+1, n*3\4, for(b=c+1, ceil(2/(t=4/n-1/c))-1, numerator(t-1/b)==1&&return(b/(b*t-1))))

CROSSREFS

Cf. A073101, A075245, A075246, A075247.

Sequence in context: A240537 A227354 A075247 * A173853 A040135 A004015

Adjacent sequences:  A257838 A257839 A257840 * A257842 A257843 A257844

KEYWORD

nonn

AUTHOR

M. F. Hasler, May 16 2015

STATUS

approved

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Last modified February 22 04:10 EST 2018. Contains 299428 sequences. (Running on oeis4.)