0,4
x[n]y is the square-bracket notation for hyperoperations.
See A054871 for details and key links.
Table of n, a(n) for n=0..5.
a(0) = 2[0]-2 = -1;
a(1) = 2[1]-1 = 1;
a(2) = 2[2]0 = 0;
a(3) = 2[3]1 = 2;
a(4) = 2[4]2 = 4;
a(6) = 2[5]3 = 65536;
a(7) = 2[6]4 = 2[6]2[6]2 = 2[7]3.
Cf. A001695 (2[n]n).
Sequence in context: A070655 A006263 A266198 * A079236 A138852 A062701
Adjacent sequences: A274987 A274988 A274989 * A274991 A274992 A274993
sign
Natan Arie Consigli, Sep 24 2016
approved