OFFSET
1,3
REFERENCES
J.-P. Allouche and J. Shallit, Automatic Sequences, Cambridge, 2003, Section 14.5.
LINKS
W. Penney, A "binary" system for complex numbers, J. ACM 12 (1965), 247-248.
FORMULA
There is an automaton of 21 states that accepts the base-2 representation of members of this sequence.
EXAMPLE
9 is in the sequence, since 9 in base 2 is 1001, which is 3+2i in base (-1+i).
MATHEMATICA
Select[Range[0, 260], Min[ReIm[FromDigits[IntegerDigits[#, 2], I - 1]]] >= 0 &] (* Amiram Eldar, Jun 29 2023 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Jeffrey Shallit, Jun 29 2023
STATUS
approved