

A056849


Final digit of n^n.


15



1, 4, 7, 6, 5, 6, 3, 6, 9, 0, 1, 6, 3, 6, 5, 6, 7, 4, 9, 0, 1, 4, 7, 6, 5, 6, 3, 6, 9, 0, 1, 6, 3, 6, 5, 6, 7, 4, 9, 0, 1, 4, 7, 6, 5, 6, 3, 6, 9, 0, 1, 6, 3, 6, 5, 6, 7, 4, 9, 0, 1, 4, 7, 6, 5, 6, 3, 6, 9, 0, 1, 6, 3, 6, 5, 6, 7, 4, 9, 0, 1, 4, 7, 6, 5, 6, 3, 6, 9, 0, 1, 6, 3, 6, 5, 6, 7, 4, 9, 0
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OFFSET

1,2


COMMENTS

Cyclic with a period of 20.
Also decimal expansion of 147656369016365674900/(10^201).  Bruno Berselli, Sep 27 2021


REFERENCES

R. Euler and J. Sadek, "A Number That Gives The Units Of n^n", Journal of Recreational Mathematics, vol. 29(3), 1998, pp. 2034.


LINKS

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


MAPLE

seq(n &^ n mod 10, n=1..120);


MATHEMATICA

Table[PowerMod[n, n, 10], {n, 1, 100}]


PROG

(Magma) [Modexp(n, n, 10): n in [1..100]]; // Bruno Berselli, Sep 27 2021
(Python)
def a(n): return pow(n, n, 10)


CROSSREFS



KEYWORD

nonn,base,easy


AUTHOR



STATUS

approved



