login
Squares mod 49.
2

%I #24 Jan 12 2024 06:41:06

%S 0,1,2,4,8,9,11,15,16,18,22,23,25,29,30,32,36,37,39,43,44,46

%N Squares mod 49.

%F a(n) = a(n-1) + a(n-3) - a(n-4) for 5 < n <= 22. - _Chai Wah Wu_, Jan 30 2018

%t Union[PowerMod[Range[49], 2, 49]] (* _Alonso del Arte_, Jan 07 2020 *)

%o (Sage) [quadratic_residues(49)] # _Zerinvary Lajos_, May 24 2009

%o (Scala) (1 to 49).map(n => n * n % 49).toSet.toSeq.sorted // _Alonso del Arte_, Jan 07 2020

%Y Cf. A028762, A010459.

%Y Row 49 of A096008.

%K nonn,fini,full,easy

%O 1,3

%A _N. J. A. Sloane_