OFFSET
0,2
COMMENTS
a(n) = height of lattice of orthogonal arrays with 2^2^n runs.
LINKS
FORMULA
a(n) converges to nearest integer to c*(2^(2^n)-1), where c = 1.403936827882178... (see A048649).
MATHEMATICA
RecurrenceTable[{a[0]==1, a[n]==1+(2^(2^(n-1))+1)a[n-1]}, a, {n, 10}] (* Harvey P. Dale, Dec 13 2013 *)
CROSSREFS
KEYWORD
nonn,nice,easy
AUTHOR
N. J. A. Sloane, E. M. Rains
STATUS
approved