OFFSET
1,2
LINKS
Eric Weisstein's World of Mathematics, Grid Graph
Eric Weisstein's World of Mathematics, Harary Index
EXAMPLE
0, 5, 133/6, 293/5, 3399/28, 137111/630, 140351/396, ...
MATHEMATICA
Table[n (2 n + 1) (2 + (2 n - 1) Derivative[1][Log[CatalanNumber[# - 1]] &][n] - n)/3, {n, 20}] // FullSimplify // Numerator
Table[n (2 n + 1) (2 + (2 n - 1) (HarmonicNumber[n - 3/2] - HarmonicNumber[n] + 2 Log[2]) - n)/3, {n, 20}] // FunctionExpand // FullSimplify // Numerator
CROSSREFS
KEYWORD
nonn,frac
AUTHOR
Eric W. Weisstein, Dec 07 2017
STATUS
approved