A005929 Theta series of hexagonal net with respect to midpoint of edge. (Formerly M0006)

0, 2, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 0, 6, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 8, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 0, 4, 0

Offset

0,2

References

N. J. A. Sloane, Theta series and magic numbers for diamond and certain ionic crystal structures, J. Math. Phys. 28 (1987), 1653-1657.

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

Table of n, a(n) for n=0..104.

Maple

theta2:=x->add(2*x^((2*n-1)^2/4), n=1..200): phi1:=x->theta2(x^(1/4))*theta2(x^(3/4))/2: seq(coeff(convert(series(phi1(x^4)-phi1(x^12), x, 200), polynom), x, n), n=0..200); # Herman Jamke (hermanjamke(AT)fastmail.fm), Feb 28 2008

Crossrefs

Sequence in context: A028833 A024943 A325787 * A005871 A005888 A213902

Adjacent sequences: A005926 A005927 A005928 * A005930 A005931 A005932

Keyword

easy,nonn

Author

N. J. A. Sloane

Extensions

More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Feb 28 2008

Status

approved