A365936 Final digit (in decimal system) of n^(n-1) = A000169(n).

1, 2, 9, 4, 5, 6, 9, 2, 1, 0, 1, 8, 1, 4, 5, 6, 1, 8, 1, 0, 1, 2, 9, 4, 5, 6, 9, 2, 1, 0, 1, 8, 1, 4, 5, 6, 1, 8, 1, 0, 1, 2, 9, 4, 5, 6, 9, 2, 1, 0, 1, 8, 1, 4, 5, 6, 1, 8, 1, 0, 1, 2, 9, 4, 5, 6, 9, 2, 1, 0, 1, 8, 1, 4, 5, 6, 1, 8, 1, 0, 1, 2, 9, 4, 5, 6, 9

Offset: 1

Author

Marco Ripà, Sep 23 2023

Keywords

• nonn
• base
• easy

Comments

This is a periodic sequence with period 20 which is twice the considered radix.

Examples

			For n = 4, a(4) = 4^3 mod 10 = 64 mod 10 = 4.
		

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).

Crossrefs

Cf. A000169, A056849, A120962, A138029, A365707.

Programs

Mathematica

a[n_]:=Last[IntegerDigits[n^(n-1)]]; Array[a,87] (* Stefano Spezia, Sep 26 2023 *)

Formula

a(n) = n^(n-1) mod 10.

a(n) = A365935(n+10).