Information on mass chains and nuclides available on this website:

WWW TUNL

¹⁸Be has not been observed: it is predicted to have a mass excess of 78.43 MeV (JA76M; and see (WA76L)). ¹⁸Be is then unstable with respect to breakup into ¹⁶Be + 2n, ¹⁵Be + 3n, ¹⁴Be + 4n, ¹³Be + 5n, ¹²Be + 6n, ¹¹Be + 7n and ¹⁰Be + 8n by, respectively, 3.02, 3.01, 5.42, 2.88, 4.99, 1.75 and 1.25 MeV (using the (WA76L) masses for the residual nuclei). See also (TH74).