A081643 Integers congruent to 0, 1, 4 or 9 (mod 16) which are not squares.

17, 20, 32, 33, 41, 48, 52, 57, 65, 68, 73, 80, 84, 89, 96, 97, 105, 112, 113, 116, 128, 129, 132, 137, 145, 148, 153, 160, 161, 164, 176, 177, 180, 185, 192, 193, 201, 208, 209, 212, 217, 224, 228, 233, 240, 241, 244, 249, 257, 260, 265, 272, 273, 276, 281

Offset: 1

Author

Robert G. Wilson v, Mar 26 2003

Keywords

• easy
• nonn

References

• Mark A. Herkommer, Number Theory, A Programmer's Guide, McGraw-Hill, New York, 1999, page 315.

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000

Programs

Mathematica

Select[ Range[287], (Mod[ #, 16] == 0 || Mod[ #, 16] == 1 || Mod[ #, 16] == 4 || Mod[ #, 16] == 9) && !IntegerQ[ Sqrt[ # ]] & ]
Select[Range[300],MemberQ[{0,1,4,9},Mod[#,16]]&&!IntegerQ[Sqrt[#]]&] (* Harvey P. Dale, Jul 29 2019 *)