A027747 a(n) = n^n^n^..^n (6-n terms, n<=5).

1, 1, 65536, 7625597484987, 256, 5

Offset

0,3

Comments

The creator of the test asked me to remove this sequence. But one of the reasons for creating this database was to help people do these tests. This was stated already in the 1973 Handbook of Integer Sequences. Many sequences in the database have appeared on IQ tests.

Links

Table of n, a(n) for n=0..5.

P. Cooijmans, Test for Genius (Short Form) [broken link]

Paul Cooijmans, Numbers.

Paul Cooijmans, Short Test For Genius.

Example

a(0) = 0^(0^(0^(0^(0^0)))) = 1.
a(1) = 1^(1^(1^(1^1))) = 1.
a(2) = 2^(2^(2^2)) = 2^16.
a(3) = 3^(3^3) = 3^27.
a(4) = 4^4.
a(5) = 5.

Maple

b:= (n, i)-> `if`(i=0, 1, n^b(n, i-1)):
a:= n-> b(n, 6-n):
seq(a(n), n=0..5);  # Alois P. Heinz, Aug 22 2017

Prog

(PARI) a(n) = if (n<=1,  1, if (n==3, n^(6-n)^3, n^(6-n)^2)); \\ Bruce Nye, Jun 05 2026

Crossrefs

Cf. A004231, A049384, A051441.

Diagonal d=6 of A321312.

Sequence in context: A017444 A017576 A013881 * A255323 A351314 A051332

Adjacent sequences: A027744 A027745 A027746 * A027748 A027749 A027750

Keyword

nonn,fini,full

Author

Sent in by an anonymous correspondent

Extensions

Examples from Martin Renner, Aug 22 2017

a(0)=1 prepended by Alois P. Heinz, Jun 05 2026

Status

approved