OFFSET
1,1
FORMULA
For n==0 (mod 4), a(n) = 3^n; for n==1,3 (mod 4), a(n) = 11^n; for n==2 (mod 4), a(n)=9^n. - Max Alekseyev, Dec 06 2013
MATHEMATICA
snp[n_]:=Module[{k=2}, While[PowerMod[k, n, 10]!=1, k++]; k^n]; Array[snp, 30] (* Harvey P. Dale, Aug 07 2023 *)
PROG
(PARI) a(n) = [3, 11, 9, 11][n%4+1]^n
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Amarnath Murthy, Jul 07 2003
EXTENSIONS
Description corrected by Ray Chandler, Jul 08 2003
More terms from Ray Chandler, Jul 11 2003
STATUS
approved