OFFSET
1,3
FORMULA
a(n) = a(n-1) + a(n-3) - a(n-4) for 5 < n <= 22. - Chai Wah Wu, Jan 30 2018
MATHEMATICA
Union[PowerMod[Range[49], 2, 49]] (* Alonso del Arte, Jan 07 2020 *)
PROG
(Sage) [quadratic_residues(49)] # Zerinvary Lajos, May 24 2009
(Scala) (1 to 49).map(n => n * n % 49).toSet.toSeq.sorted // Alonso del Arte, Jan 07 2020
KEYWORD
nonn,fini,full,easy
AUTHOR
STATUS
approved