

A279198


Number of pairs of conjugate inseparable solutions of X + Y = 2Z (integer, disjoint triples from {1,2,3,...,3n}).


6



0, 0, 0, 2, 7, 52, 297, 1994, 14594, 113794, 991741, 9199390, 94105010, 1015012796, 11914379971, 146974330141, 1954701366709
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OFFSET

1,4


REFERENCES

R. K. Guy, Sedlacek's Conjecture on Disjoint Solutions of x+y= z, Univ. Calgary, Dept. Mathematics, Research Paper No. 129, 1971.
R. K. Guy, Sedlacek's Conjecture on Disjoint Solutions of x+y= z, in Proc. Conf. Number Theory. Pullman, WA, 1971, pp. 221223.
R. K. Guy, Packing [1,n] with solutions of ax + by = cz; the unity of combinatorics, in Colloq. Internaz. Teorie Combinatorie. Rome, 1973, Atti Conv. Lincei. Vol. 17, Part II, pp. 173179, 1976.
Nowakowski, Richard Joseph, Generalization of the LangfordSkolem problem, MS Thesis, University of Calgary, 1975.


LINKS

Table of n, a(n) for n=1..17.
R. K. Guy, Letter to N. J. A. Sloane, June 24 1971: front, back [Annotated scanned copy, with permission] See sequence "J".
R. J. Nowakowski, Generalizations of the LangfordSkolem problem, M.S. Thesis, Dept. Math., Univ. Calgary, May 1975. [Scanned copy, with permission.]


FORMULA

A279197(n) + 2*A279198(n) = A202705(n).


EXAMPLE

Richard Guy gives examples in his letter.


CROSSREFS

All of A279197, A279198, A202705, A279199, A104429, A282615 are concerned with counting solutions to X+Y=2Z in various ways.
See also A002848, A002849.
Sequence in context: A265042 A249754 A224879 * A220092 A138737 A216086
Adjacent sequences: A279195 A279196 A279197 * A279199 A279200 A279201


KEYWORD

nonn,more


AUTHOR

N. J. A. Sloane, Dec 15 2016


EXTENSIONS

a(7)a(16) from Fausto A. C. Cariboni, Feb 27 2017
a(17) from Fausto A. C. Cariboni, Mar 22 2017


STATUS

approved



