A132777 Nonsquare numbers which are the sum of 2 distinct squares.

5, 10, 13, 17, 20, 26, 29, 34, 37, 40, 41, 45, 50, 52, 53, 58, 61, 65, 68, 73, 74, 80, 82, 85, 89, 90, 97, 101, 104, 106, 109, 113, 116, 117, 122, 125, 130, 136, 137, 145, 146, 148, 149, 153, 157, 160, 164

Offset

1,1

Comments

This is simply A001983 excluding the square numbers.

The squares of these numbers are also sums of two distinct nonzero squares. Including them gives A004431. - Jean-Christophe Hervé, Nov 11 2013

Links

Table of n, a(n) for n=1..47.

Example

5 = 4 + 1, and 5^2 = 16 + 9 ; 10 = 9 + 1, and 10^2 = 64 + 36. - Jean-Christophe Hervé, Nov 11 2013

Mathematica

selQ[n_] := !IntegerQ[Sqrt[n]] && Select[ PowersRepresentations[n, 2, 2], 0 <= #[[1]] < #[[2]]&] != {};
Select[Range[1000], selQ] (* Jean-François Alcover, Apr 20 2023 *)

Crossrefs

Cf. A001983, A004431.

Sequence in context: A055096 A313386 A267969 * A191217 A230779 A313387

Adjacent sequences: A132774 A132775 A132776 * A132778 A132779 A132780

Keyword

easy,nonn

Author

Rob Hubbard (hubbard.r(AT)gmail.com), Oct 08 2007

Extensions

Definition corrected by Jean-Christophe Hervé, Nov 11 2013

Status

approved