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A141497 Conjectured to be complete list of numbers not of the form 2*x^2 + 4*triangular number + 5*triangular number. 8
1, 3, 10, 16, 28, 43, 46, 85, 169, 175, 211, 223 (list; graph; refs; listen; history; text; internal format)
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-Fran├žois Alcover, Oct 01 2018 *)

CROSSREFS

Cf. A141464, A141491.

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

Sequence in context: A063209 A063109 A083684 * A059911 A160375 A300017

Adjacent sequences:  A141494 A141495 A141496 * A141498 A141499 A141500

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Sep 05 2008

STATUS

approved

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Last modified October 15 20:04 EDT 2019. Contains 328037 sequences. (Running on oeis4.)