0,5

Table of n, a(n) for n=0..8.

R. S. Nickerson, Problem E1845, Amer. Math. Monthly, p. 81, 73 (1966).

R. S. Nickerson and D. C. B. Marsh, E1845: A variant of Langford's Problem, American Math. Monthly, 1967, 74, 591-595.

R. J. Nowakowski, Generalizations of the Langford-Skolem problem, M.S. Thesis, Dept. Math., Univ. Calgary, May 1975. [Scanned copy, with permission.]

Cf. A108235, A202952.

Sequence in context: A159190 A236766 A004075 * A316633 A295052 A343369

Adjacent sequences: A202948 A202949 A202950 * A202952 A202953 A202954

nonn,more

N. J. A. Sloane, Dec 26 2011

approved