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A081642
Integers congruent to 0, 1 or 4 (mod 9) which are not squares.
1
10, 13, 18, 19, 22, 27, 28, 31, 37, 40, 45, 46, 54, 55, 58, 63, 67, 72, 73, 76, 82, 85, 90, 91, 94, 99, 103, 108, 109, 112, 117, 118, 126, 127, 130, 135, 136, 139, 145, 148, 153, 154, 157, 162, 163, 166, 171, 172, 175, 180, 181, 184, 189, 190, 193, 198, 199, 202
OFFSET
1,1
REFERENCES
Mark A. Herkommer, Number Theory, A Programmer's Guide, McGraw-Hill, New York, 1999, page 315.
MATHEMATICA
Select[ Range[206], (Mod[ #, 9] == 0 || Mod[ #, 9] == 1 || Mod[ #, 9] == 4) && !IntegerQ[ Sqrt[ # ]] & ]
Select[Flatten[#+{0, 1, 4}&/@(9*Range[0, 30])], !IntegerQ[Sqrt[#]]&] (* Harvey P. Dale, Dec 29 2019 *)
CROSSREFS
Cf. A028837.
Sequence in context: A335016 A240109 A163652 * A174274 A120155 A363079
KEYWORD
easy,nonn
AUTHOR
Robert G. Wilson v, Mar 26 2003
STATUS
approved