A000548 Squares that are not the sum of 2 nonzero squares.

1, 4, 9, 16, 36, 49, 64, 81, 121, 144, 196, 256, 324, 361, 441, 484, 529, 576, 729, 784, 961, 1024, 1089, 1296, 1444, 1764, 1849, 1936, 2116, 2209, 2304, 2401, 2916, 3136, 3249, 3481, 3844, 3969, 4096, 4356, 4489

Offset: 1

Author

N. J. A. Sloane and J. H. Conway

Keywords

• nonn

Comments

Squares of nonhypotenuse numbers A004144(n). - Lekraj Beedassy, Jul 06 2004

A143574(a(n)) = a(n); intersection of A000290 and A143575. - Reinhard Zumkeller, Aug 24 2008

Links

• R. Zumkeller, Table of n, a(n) for n = 1..1000
• Index entries for sequences related to sums of squares

Programs

Mathematica

okQ[n_] := n == 1 || AllTrue[FactorInteger[n][[All, 1]], Mod[#, 4] != 1& ]; A000548 = Select[Range[100], okQ]^2 (* Jean-François Alcover, Feb 09 2016 *)

Formula

A000290 \ A134422. - R. J. Mathar, Feb 06 2011