A141464 Conjectured to be complete list of numbers not of the form 4*x^2 + 3*triangular number + triangular number.

2, 11, 27, 38, 86, 93, 188, 323

Offset

1,1

Links

Table of n, a(n) for n=1..8.

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 <= 400, n++, If[FindInstance[n == 4x^2 + 3y(y+1)/2 + z(z+1)/2, {x, y, z}, Integers] == {}, Print[n]; Sow[n]]]][[2, 1]] (* Jean-François Alcover, Oct 01 2018 *)

Crossrefs

Cf. A141491, A141497.

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

Sequence in context: A080663 A248118 A320648 * A218471 A139211 A254196

Adjacent sequences: A141461 A141462 A141463 * A141465 A141466 A141467

Keyword

nonn

Author

N. J. A. Sloane, Sep 05 2008

Status

approved