A350864 Nonprimes that are not the sum of 2 nonzero squares.

1, 4, 6, 12, 14, 15, 21, 22, 24, 27, 28, 30, 33, 35, 38, 39, 42, 44, 46, 48, 51, 54, 55, 56, 57, 60, 62, 63, 66, 69, 70, 75, 76, 77, 78, 84, 86, 87, 88, 91, 92, 93, 94, 95, 96, 99, 102, 105, 108, 110, 111, 112, 114, 115, 118, 119, 120, 123, 124, 126, 129, 132

Offset: 1

Author

Robert P. P. McKone, Jan 19 2022

Keywords

• nonn

Comments

a(1) = 1 and a(2) = 4 are squares, but are not the sum of two nonzero squares. If zero were allowed, then 1 and 4 would not be terms, since 1 = 1 + 0 and 4 = 4 + 0.

Crossrefs

Intersection of A018252 and A018825.

Cf. A001481.

Programs

Mathematica

a[n_] := Complement[Table[m, {m, 1, n}], Table[Prime[m], {m, 1, PrimePi[n]}], Select[Range[5, n], SquaresR[2, #] != 0 &]]; a[132]