A088666 - OEIS

A088666

a(n) = (n^4 + 1) mod 10.

1, 2, 7, 2, 7, 6, 7, 2, 7, 2, 1, 2, 7, 2, 7, 6, 7, 2, 7, 2, 1, 2, 7, 2, 7, 6, 7, 2, 7, 2, 1, 2, 7, 2, 7, 6, 7, 2, 7, 2, 1, 2, 7, 2, 7, 6, 7, 2, 7, 2, 1, 2, 7, 2, 7, 6, 7, 2, 7, 2, 1, 2, 7, 2, 7, 6, 7, 2, 7, 2, 1, 2, 7, 2, 7, 6, 7, 2, 7, 2, 1, 2, 7, 2, 7, 6, 7, 2, 7, 2

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,2

COMMENTS

Periodic, with period 10. - Harvey P. Dale, Jan 31 2015

LINKS

Harvey P. Dale, Table of n, a(n) for n = 0..1000

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

FORMULA

a(n) = A010879(A002523(n)). - Michel Marcus, Feb 01 2015

MATHEMATICA

PowerMod[Range[0, 90], 4, 10]+1 (* or *) PadRight[{}, 100, {1, 2, 7, 2, 7, 6, 7, 2, 7, 2}] (* Harvey P. Dale, Jan 31 2015 *)