A120962 Final digit (in decimal system) of n^(n^n), i.e., n^(n^n) mod 10.

0, 1, 6, 7, 6, 5, 6, 3, 6, 9, 0, 1, 6, 3, 6, 5, 6, 7, 6, 9, 0, 1, 6, 7, 6, 5, 6, 3, 6, 9, 0, 1, 6, 3, 6, 5, 6, 7, 6, 9, 0, 1, 6, 7, 6, 5, 6, 3, 6, 9, 0, 1, 6, 3, 6, 5, 6, 7, 6, 9, 0, 1, 6, 7, 6, 5, 6, 3, 6, 9, 0, 1, 6, 3, 6, 5, 6, 7, 6, 9, 0, 1, 6, 7, 6, 5, 6, 3, 6, 9, 0, 1, 6, 3, 6, 5, 6, 7, 6, 9, 0, 1, 6, 7, 6, 5

Offset

0,3

Comments

Periodic sequence with period length 20. - Arkadiusz Wesolowski, Feb 12 2012

Links

Table of n, a(n) for n=0..105.

Index entries for linear recurrences with constant coefficients, signature (0,1,0,-1,0,1,0,-1,0,1,0,-1,0,1,0,-1,0,1).

Formula

a(n) = A010879(A002488(n)). - Michel Marcus, Aug 04 2015

Maple

seq(n &^ (n^n) mod 10, n=0..105);

Mathematica

Join[{0}, Table[PowerMod[n, n^n, 10], {n, 100}]] (* Stefan Steinerberger, Nov 23 2007 *)

Prog

(PARI) a(n)=if(n%10, lift(Mod(n, 10)^lift(Mod(n, 20)^n)), 0) \\ Charles R Greathouse IV, Feb 12 2012
(Python)
def A120962(n): return pow(n, n**n, 10) # Chai Wah Wu, Sep 22 2023

Crossrefs

Cf. A061505, A229522, A229784.

Sequence in context: A369104 A253271 A258945 * A355922 A261024 A343436

Adjacent sequences: A120959 A120960 A120961 * A120963 A120964 A120965

Keyword

nonn,base,easy

Author

N. J. A. Sloane, Jul 19 2006, Oct 26 2007

Extensions

More terms from Stefan Steinerberger, Nov 23 2007

Status

approved