A316489 Positive numbers of the form 8*k + 4 that cannot be expressed as the sum of four distinct odd squares.

4, 12, 20, 28, 36, 44, 52, 60, 68, 76, 92, 100, 108, 124, 132, 148, 172, 188, 220, 268, 292, 388, 412

Offset

1,1

Comments

There are no more terms through 10^11. It seems extremely unlikely that any more terms exist.

Every odd square is a number of the form 8*k + 1, so every sum of four odd squares is a number of the form 8*k + 4.

A316834 lists all numbers that can be expressed in only one way as the sum of four distinct odd squares.

Links

Table of n, a(n) for n=1..23.

Crossrefs

Cf. A316834.

Sequence in context: A328304 A031065 A017113 * A081770 A062876 A301098

Adjacent sequences: A316486 A316487 A316488 * A316490 A316491 A316492

Keyword

nonn

Author

Jon E. Schoenfield, Jul 27 2018

Status

approved