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A257840
y-value of the lexicographically first integer solution (x,y,z) of 4/n = 1/x + 1/y + 1/z with 0 < x < y < z, or 0 if there is no such solution. Corresponding x and z values are in A257839 and A257841.
6
0, 0, 4, 3, 4, 7, 15, 7, 10, 16, 34, 13, 18, 29, 61, 21, 30, 46, 96, 31, 43, 67, 139, 43, 60, 92, 190, 57, 78, 121, 249, 73, 100, 154, 316, 91, 124, 191, 391, 111, 154, 232, 474, 133, 181, 277, 565, 157, 99, 326, 664, 183, 248, 379, 771, 211, 286, 436, 886, 241, 326, 497, 1009, 273, 370, 562, 1140, 307, 415, 631, 1279, 343, 210, 704, 1426, 381, 514, 781, 1581, 421
OFFSET
1,3
COMMENTS
See A073101 for more details.
This differs from A075246 starting with a(89)=690 vs A075246(89)=306, corresponding to the representations 4/89 = 1/23 + 1/690 + 1/61410 = 1/24 + 1/306 + 1/108936.
LINKS
PROG
(PARI) apply( {A257840(n, t)=for(x=n\4+1, 3*n\4, for(y=max(1\t=4/n-1/x, x)+1, ceil(2/t)-1, numerator(t-1/y)==1 && return(y)))}, [1..99]) \\ improved by M. F. Hasler, Jul 03 2022
CROSSREFS
KEYWORD
nonn
AUTHOR
M. F. Hasler, May 16 2015
STATUS
approved