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A306718 Numbers not of the form x^2+y^2+14*z^2. 1
3, 6, 7, 11, 12, 21, 28, 33, 35, 38, 42, 44, 47, 62, 70, 71, 77, 83, 84, 91, 102, 107, 110, 119, 132, 133, 140, 147, 161, 168, 182, 188, 189, 203, 217, 231, 238, 266, 267, 278, 280, 284, 287, 294, 308, 315, 318, 329, 332, 335, 336, 343, 357, 364, 378, 385 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Robert Israel, Table of n, a(n) for n = 1..10000

Irving Kaplansky, The first nontrivial genus of positive definite ternary forms, Mathematics of Computation, Vol. 64 (1995): 341-345.

MAPLE

N:= 1000: # for terms <= N

V:= Array(0..N):

for x from 0 to floor(sqrt(N/2)) do

for y from x while x^2 + y^2 <= N do

for z from 0 do

v:= x^2 + y^2 + 14*z^2;

if v > N then break fi;

V[v]:= 1;

od od od:

select(t -> V[t]=0, [$1..N]); # Robert Israel, Mar 27 2019

CROSSREFS

Sequence in context: A120511 A176864 A347793 * A022550 A237883 A153033

Adjacent sequences: A306715 A306716 A306717 * A306719 A306720 A306721

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Mar 26 2019

STATUS

approved

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Last modified January 27 21:49 EST 2023. Contains 359849 sequences. (Running on oeis4.)