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Numbers of form 8k+1 which are not squares.
1

%I #4 May 03 2018 10:29:44

%S 17,33,41,57,65,73,89,97,105,113,129,137,145,153,161,177,185,193,201,

%T 209,217,233,241,249,257,265,273,281,297,305,313,321,329,337,345,353,

%U 369,377,385,393,401,409,417,425,433,449,457,465,473,481,489,497,505

%N Numbers of form 8k+1 which are not squares.

%t a = {}; Do[If[Sqrt[8k + 1] == Floor[Sqrt[8k + 1]],[null],AppendTo[a, 8k + 1]], {k, 0, 100}]; a

%t Select[8*Range[80]+1,!IntegerQ[Sqrt[#]]&] (* _Harvey P. Dale_, May 03 2018 *)

%Y Cf. A004768, A017077.

%K nonn

%O 1,1

%A _Artur Jasinski_, Mar 18 2008