A037041 Number of quadratic residues mod n for some n (A000224 sorted and duplicates removed).

1, 2, 3, 4, 6, 7, 8, 9, 10, 11, 12, 14, 15, 16, 18, 19, 20, 21, 22, 23, 24, 27, 28, 30, 31, 32, 33, 34, 36, 37, 38, 40, 42, 44, 45, 46, 48, 49, 51, 52, 53, 54, 55, 56, 57, 60, 62, 63, 64, 66, 68, 69, 70, 72, 74, 75, 76, 77, 79, 80, 81, 82, 84, 87, 88, 90, 91, 92, 93, 96, 97, 98

Offset: 1

Author

David W. Wilson

Keywords

• nonn

Links

• Robert Israel, Table of n, a(n) for n = 1..1802

Programs

Maple

N:= 100: # for terms <= N
S:= {}:
for i from 1 to N^2 do
  v:= A000224(i);
  if v <= N then
    S:= S union {v}
  fi;
od:
sort(convert(S,list)); # Robert Israel, Jul 20 2025