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A141423 Conjectured to be complete list of numbers not of the form 3*x^2 + 4*y^2 + triangular number. 8
2, 11, 23, 50, 116, 135, 138 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..7.

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 <= 200, n++, If[FindInstance[n == 3x^2 + 4y^2 + z(z+1)/2, {x, y, z}, Integers] == {}, Print[n]; Sow[n]]]][[2, 1]] (* Jean-François Alcover, Oct 01 2018 *)

CROSSREFS

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

Cf. A141464, A141491, A141497.

Sequence in context: A126916 A090424 A056637 * A106974 A198277 A218046

Adjacent sequences:  A141420 A141421 A141422 * A141424 A141425 A141426

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Sep 05 2008

STATUS

approved

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Last modified August 22 12:34 EDT 2019. Contains 326177 sequences. (Running on oeis4.)