Numbers k with the property that k is the next lexicographically earliest number that cannot be expressed as a linear sum of the squares of preceding terms of the sequence with coefficients of 0, +1 or -1, with a(1)=1.

A390487

Numbers k with the property that k is the next lexicographically earliest number that cannot be expressed as a linear sum of the squares of preceding terms of the sequence with coefficients of 0, +1 or -1, with a(1)=1.