0,2

a[n]b is the square-bracket notation for n-th hyperoperation of a times b see A054871 for more info.

Table of n, a(n) for n=0..4.

a(0) = 1;

a(1) = a(0)[0]a(0) = 1’= 2;

a(2) = a(1)[1]a(1) = 2+2 = 4;

a(3) = a(2)[2]a(2) = 4*4 = 16;

a(4) = a(3)[3]a(3) = 16^16 = 18446744073709551616.

Cf. A271551.

Sequence in context: A124436 A014221 A249760 * A105510 A155951 A208132

Adjacent sequences: A271549 A271550 A271551 * A271553 A271554 A271555

nonn

Natan Arie Consigli, Apr 09 2016

approved