1,2

W.-J. Tzeng and F. Y. Wu, Spanning Trees on Hypercubic Lattices and Non-orientable Surfaces

a(n) = 2^(n^3-1) / n^3 * product n1=0..n-1 n2=0..n-1 n3=0..n-1 (3- cos(PI*n1/n) - cos(PI*n2/n) - cos(PI*n3/n) ) where n1, n2, n3 are not all 0.

Cf. A007341.

Sequence in context: A023098 A008692 A067518 this_sequence A069043 A013591 A065110

Adjacent sequences: A071760 A071761 A071762 this_sequence A071764 A071765 A071766

nonn

Sharon Sela (sharonsela(AT)hotmail.com), Jun 04 2002