This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified October 20 23:39 EDT 2018. Contains 316405 sequences. (Running on oeis4.)