

A275169


Positive integers not in the form x^3 + 2*y^2 + z^2 with x,y,z nonnegative integers.


3



15, 21, 47, 53, 79, 85, 92, 111, 117, 120, 181, 183, 245, 309, 311, 335, 372, 373, 398, 405, 421, 437, 447, 501, 565, 573, 629, 636, 645, 655, 693, 757, 791, 807, 820, 821, 853, 869, 885, 888, 949, 967, 1013, 1045, 1077, 1141, 1205, 1223, 1269, 1271, 1303, 1461, 1555, 1591, 1613, 1653, 2087, 2101, 2255, 2421
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,1


COMMENTS

Conjecture: The sequence has totally 174 terms as listed in the bfile the largest of which is 375565.
This implies the conjecture in A275150. We note that the sequence contains no term greater than 375565 and not exceeding 10^6.
See also A275168 for a similar conjecture.


LINKS

ZhiWei Sun, Table of n, a(n) for n = 1..174


EXAMPLE

a(1) = 15 since 15 is the least positive integer not in the form x^3 + 2*y^2 + z^2 with x,y,z nonnegative integers.


MATHEMATICA

SQ[n_]:=SQ[n]=IntegerQ[Sqrt[n]]
n=0; Do[Do[If[SQ[mx^32*y^2], Goto[aa]], {x, 0, m^(1/3)}, {y, 0, Sqrt[(mx^3)/2]}]; n=n+1; Print[n, " ", m]; Label[aa]; Continue, {m, 1, 2421}]


CROSSREFS

Cf. A000290, A000578, A022551, A022552, A262813, A270488, A274274, A275083, A275150, A275168.
Sequence in context: A247021 A129752 A015831 * A063176 A083372 A119101
Adjacent sequences: A275166 A275167 A275168 * A275170 A275171 A275172


KEYWORD

nonn


AUTHOR

ZhiWei Sun, Jul 18 2016


STATUS

approved



