A081648 Integers congruent to 0, 1, 4, 9, 16, 25, 36, 49 or 64 (mod 81) which are not squares.

82, 85, 90, 97, 106, 117, 130, 145, 162, 163, 166, 171, 178, 187, 198, 211, 226, 243, 244, 247, 252, 259, 268, 279, 292, 307, 325, 328, 333, 340, 349, 360, 373, 388, 405, 406, 409, 414, 421, 430, 454, 469, 486, 487, 490, 495, 502, 511, 522, 535, 550, 567

Offset

1,1

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

Mathematica

Select[ Range[567], (Mod[ #, 81] == 0 || Mod[ #, 81] == 1 || Mod[ #, 81] == 4 || Mod[ #, 81] == 9 || Mod[ #, 81] == 16 || Mod[ #, 81] == 25 || Mod[ #, 81] == 36 || Mod[ #, 81] == 49 || Mod[ #, 81] == 64) && !IntegerQ[ Sqrt[ # ]] & ]
Select[Range[600], IntegerQ[Sqrt[Mod[#, 81]]]&&!IntegerQ[Sqrt[#]]&] (* Harvey P. Dale, May 13 2018 *)

Crossrefs

Cf. A080151, A080160.

Sequence in context: A077684 A044982 A181468 * A281921 A303885 A305278

Adjacent sequences: A081645 A081646 A081647 * A081649 A081650 A081651

Keyword

easy,nonn

Author

Robert G. Wilson v, Mar 26 2003

Status

approved