A141497 Conjectured to be complete list of numbers not of the form 2*x^2 + 4*triangular number + 5*triangular number.

1, 3, 10, 16, 28, 43, 46, 85, 169, 175, 211, 223

Offset

1,2

Links

Table of n, a(n) for n=1..12.

Ben Kane and Zhi-Wei Sun, On almost universal mixed sums of squares and triangular numbers, arXiv:0808.2761

Mathematica

Reap[For[n = 1, n <= 300, n++, If[FindInstance[n == 2x^2 + 4y(y+1)/2 + 5z(z+1)/2, {x, y, z}, Integers] == {}, Print[n]; Sow[n]]]][[2, 1]] (* Jean-François Alcover, Oct 01 2018 *)

Crossrefs

Cf. A141464, A141491.

Cf. A141273, A141386, A141423, A141428, A141443, A141463.

Sequence in context: A063209 A063109 A083684 * A366395 A059911 A160375

Adjacent sequences: A141494 A141495 A141496 * A141498 A141499 A141500

Keyword

nonn

Author

N. J. A. Sloane, Sep 05 2008

Status

approved