OFFSET
1,3
COMMENTS
Theorem (Conway, p. 81) This ternary form represents every number from 0 to 32 except 31. Any other integer-valued ternary form not equivalent to this one fails to represent some number between 1 and 30.
REFERENCES
J. H. Conway, The Sensual (Quadratic) Form, M.A.A., 1997, p. 82.
EXAMPLE
1+2*x+2*x^2+4*x^3+4*x^4+6*x^5+8*x^6+2*x^7+10*x^8+10*x^9+2*x^10+...
PROG
(Magma) L:=LatticeWithGram(3, [2, 0, 0, 0, 4, 1, 0, 1, 8] ); T<q> := ThetaSeries(L, 500); T;
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Sep 27 2006
STATUS
approved