

A305553


Numbers that are not the sum of 2 squares and a 4th power.


0



7, 12, 15, 22, 23, 28, 31, 39, 43, 44, 47, 55, 60, 63, 67, 70, 71, 76, 78, 79, 87, 92, 93, 95, 103, 108, 111, 112, 119, 124, 127, 135, 140, 143, 151, 156, 159, 167, 168, 172, 175, 177, 183, 184, 188, 191, 192, 199, 204, 207, 214, 215, 220, 223, 231, 236
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OFFSET

1,1


COMMENTS

Numbers of the form 4*A017101(k) are terms of this sequence.
m is a term iff 16m is also.


LINKS

Table of n, a(n) for n=1..56.
W. Jagy and I. Kaplansky, Sums of Squares, Cubes and Higher Powers, Experimental Mathematics, vol. 4 (1995) pp. 169173.


MATHEMATICA

n=239;
t=Union@Flatten@Table[x^2+y^2+z^4, {x, 0, n^(1/2)}, {y, x, (nx^2)^(1/2)}, {z, 0, (nx^2y^2)^(1/4)}];
Complement[Range[0, n], t]


CROSSREFS

Subsequence of A000037, A140823 and A022544.
A004215 and A214891 are subsequences.
Cf. A017101, A022552.
Sequence in context: A138615 A210254 A071780 * A338103 A190720 A295625
Adjacent sequences: A305550 A305551 A305552 * A305554 A305555 A305556


KEYWORD

nonn


AUTHOR

XU Pingya, Jun 20 2018


STATUS

approved



