A168428 a(n) = 4^n mod 10.

1, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4, 6, 4

Offset: 0

Author

Zerinvary Lajos, Nov 25 2009

Keywords

• nonn
• easy

Links

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

Crossrefs

Cf. A000302, A010879.

Last elements of rows of A008565.

Programs

Magma

[Modexp(4, n, 10): n in [0..100]]; // Vincenzo Librandi, Jul 23 2016

Mathematica

PowerMod[4, Range[0, 25], 10] (* G. C. Greubel, Jul 22 2016 *)

PARI

a(n)=lift(Mod(4,10)^n) \\ Charles R Greathouse IV, Mar 22 2016

Sage

[power_mod(4, n, 10)for n in range(0, 94)] #

Formula

a(n) = A010879(A000302(n)). - Michel Marcus, Jul 23 2016